Jump to content

Recommended Posts

Fuel economy is a buzz phrase that most car buyers/owners want to maximize. Accordingly, car manufacturers are striving to give buyers excellent MPG.

Among newer Ch#$r%*ets, while not the most fuel-efficient models available, these are still considered by many to be "fuel efficient" (compared to say, trucks, SUVs, etc.), with figures I searched for online...:

2008 V6 malibu, FWD ... EPA-estimated 17 mpg city

2008 V8 (active fuel management) impala SS, FWD ... EPA-estimated 16 mpg city

2007 V8 (active fuel management) mc SS, FWD ... EPA-estimated 18 mpg city

Comparing ... the 2008 V8 G8 GT, RWD, has an EPA-estimated 15 mpg city

Meanwhile, the 2008 Dodge Charger V8, RWD, has an EPA-estimated 17 mpg city

...and the 2008 Dodge Charger 3.5 V6, RWD, has an EPA-estimated 19 mpg city

Highway EPA-estimated MPGs are touted the most, but for this comparison, I'm using the city EPA estimates, since my RWD Monte Carlos are used more or less in the city.

I've NEVER claimed my Monte Carlos to be fuel efficient..and I still do NOT claim that; however, comparing my real-world MPGs to EPA estimated MPGs for newer engines...imho, a few of them certainly are NOT the gas guzzlers most people see them as.... Course, options on the cars along with the type of V8/V6 engines are factors that I have not taken into account...which might be unfair.... Even so, the comparisons are intriguing to me...and, with no car payments (versus a car payment with a newer car) and lower insurance premiums for the older cars (vs higher insurance premiums for a newer car), I'll stick with my older cars...for now, anyway....

1972 MC, 350 V8

... 1st 2008 fill-up, June 1 ... 15.18 MPG

... 2nd 2008 fill-up, July 4, after ~142 miles, 10.215 gallons .... 13.87 MPG

1976 MC, 305 V8

... 1st 2008 fill-up, June 1 ... 13.58 MPG

... 2nd 2008 fill-up, July 4, after ~137 miles, 10.095 gallons ... 13.58 MPG

1979 MC, 350 V8

... 1st 2008 fill-up, June 1 ... 15.47 MPG

... 2nd 2008 fill-up, July 4, after ~141 miles, 7.859 gallons ... 17.94 MPG

1981 MC, 3.8 V6

... 1st 2008 fill-up, June 1 ... 18.60 MPG

... 2nd 2008 fill-up, July 4, after ~139 miles, 7.086 gallons ... 19.62 MPG

1987 MC LS, 305 V8

... June 1 ... 19.26 MPG

... June 8 ... 17.10 MPG

... June 13 ... 18.40 MPG

... June 18 ... 16.43 MPG

... June 22 ... 18.78 MPG

... June 30 ... 19.03 MPG

... July 6, after ~155 miles, 8.118 gallons ... 19.18 MPG

Cort:34swm."Mr Monte Carlo.Mr Road Trip".pig valve&pacemaker

WRMNshowcase.legos.HO.models.MCs.RTs.CHD = http://www.chevyasylum.com/cort

"Who do you think you're talkin' to?" ... Lee Roy Parnell ... 'What Kind Of Fool Do You Think I Am?'

Link to post
Share on other sites
curious about the transmission difference, if there is one from 72 to 79? alot had changed in the 15 years between your old and new.

Oh my yes.

I don't know the specs offhand, so I'll have to get 'em for you later. The '72 has a 3-speed, but the previous owner told me it had been replaced, and she didn't know what was put in (a bit scary)...and, when I first got the car in 2002, I sifted through the paperwork she gave me...and none of it mentioned a new tranny...so, I don't know if I'll have the specific info on that one.....

Cort:34swm."Mr Monte Carlo.Mr Road Trip".pig valve&pacemaker

WRMNshowcase.legos.HO.models.MCs.RTs.CHD = http://www.chevyasylum.com/cort

"Do you see what I see?" ... One Republic ... 'Stop and Stare'

Link to post
Share on other sites

Just filled up my mustang for the first time since I got it. 14 gallon (regular of course) fill up that took me 325.5 miles. thats 23.25 mpg. Not bad but it is about 80 percent highway and I baby a lot. Going for the smooth shifts and stuff still since I havent driven a stick since I was 16, almost 6 years ago. Only stalled once so far since I got it.

for those who don't know its a 05 GT so its the 4.6 v8 wit 5 speed stick and 3.55 rear end.

Link to post
Share on other sites

Knightfan, I wonder why the '76 gets worse mileage than the '72? Even though the 305 is in the '76 instead of a 350. Though the 305 isnt as different in that respect from a 350 as people would like us to believe. For the record this is generally what mine get.

1985 Caprice with the 305 Chevrolet V8 and 4-speed auto. About 15 town and maybe 22-23 highway.

1981 Bonneville with the 307 Olds V8 and 4-speed auto. About 16 town and about 23-24 with an occasional 25 highway.

2005 Equinox with the 3.4 liter V6 5-speed auto. About 17 town and about 24 highway.

2007 Sears lawn tractor with the 18 hp Briggs and Stratton OHV. Havent tested that, but I will let you all know what it comes up with. :lol:

As you can see they all arent hugely different. The Bonneville has always been that little bit better in that respect than the Caprice though the Caprice scoots a little bit quicker too.

Edited by 2005 EquinoxLS
Link to post
Share on other sites
Just filled up my mustang for the first time since I got it. 14 gallon (regular of course) fill up that took me 325.5 miles. thats 23.25 mpg. Not bad but it is about 80 percent highway and I baby a lot. Going for the smooth shifts and stuff still since I havent driven a stick since I was 16, almost 6 years ago. Only stalled once so far since I got it.

for those who don't know its a 05 GT so its the 4.6 v8 wit 5 speed stick and 3.55 rear end.

Link to post
Share on other sites
Just filled up my mustang for the first time since I got it. 14 gallon (regular of course) fill up that took me 325.5 miles. thats 23.25 mpg. Not bad but it is about 80 percent highway and I baby a lot. Going for the smooth shifts and stuff still since I havent driven a stick since I was 16, almost 6 years ago. Only stalled once so far since I got it.

for those who don't know its a 05 GT so its the 4.6 v8 wit 5 speed stick and 3.55 rear end.

Actually that's a damned fine car!

Chris

Link to post
Share on other sites

I sold my Yukon (sniffff....snif....) and bought a super clean 99 s-10 for $2000 as an experiment for running around & work transportation...

The 2.2 liter had a funny noise like lower end bearings....I thought it was a bad idler pulley - it was. $35.

Aired up the tires to 35psi/cold air intake/new sparks w extra gap =29 mpg mission accomplished-love it.

IMG_2394.jpg

Link to post
Share on other sites

Mianly drive the Prizm which gets 32-35 in mixed driving.

Intrepid does about 24 in mixed driving. Haven't been using it much lately, mainly because it needs a ball joint or tie-rod and I haven't gotten around to doing them yet...oh and it has no A/C so yeah.

Not sure about the GM, haven't calculated it yet, but we may take it on a trip to the western part of the state today, so that would be a good chance to calculate it.

Edited by Dodgefan
Link to post
Share on other sites

Well My caprice averages 17 with a heavy, heavy, heavy right foot. but if i head up north normally i set cruise at about 68 and average 25-26. Throttle body helps and the 200 4r trans is way more efficient than the 700r or TH350. I think the 76 needs a tuning. Or the driver needs to stop listening for the exhaust. Trust me balty the 305 doesn't need to stress much more than a 350 to pull around a car. it holds it own. 170 hp 260 ft lbs of torque.

Link to post
Share on other sites
I think the 76 needs a tuning. Or the driver needs to stop listening for the exhaust.

LOL!

I WISH it were a case of me needing to stop listening for the exhaust ;).

But, no, the '76 always seems to "drag" a little bit upon cold starts. It's fine once it gets warmed up...but, it tends to bog and, sometimes, will hesitate/stall as I drive it out of the garage. And, yep, it has been tuned up....

Cort:34swm."Mr Monte Carlo.Mr Road Trip".pig valve&pacemaker

WRMNshowcase.legos.HO.models.MCs.RTs.CHD = http://www.chevyasylum.com/cort

"I ain't ready for the junkyard yet" ... George Jones ... 'I Don't Need Your Rocking Chair'

Link to post
Share on other sites

The choke probably just needs adjusting Cort. Seemed like in those days they adjusted the choke to come off as quickly as possible. Problem is that if you go to far with that kind of thinking it makes the car want to stall while it is warming up. Also make sure your Thermac is working right. If the door in the tube leading to the air cleaner sticks open and doesnt close when its cold it will suck cold air while it is warming up causing it to stumble and also it wont warm up as fast causing poor fuel economy. Just a few things to think about. Another question not related to this, does the 305 in the '76 ping at all or is it pretty quiet. Thats was a horrible problem on the 1979 Impala I had with the 305 and also on Mom and Dads 1978 Impala with that motor. Not a problem on the 1985 Caprice since that has a knock sensor.

Capriceman, are you sure yours has a 200-4R? My 1985 has the 700-R4. Mine gets about 15-16 town and 23-24 highway. I should replace the spark plugs in it though before winter comes again. Mine is bone stock just as it came from GM in December of 1984. Did you get your all fixed from when it got stolen? I would like to replace the radio in mine with something modern but I hate to see that part of the dash get cut up. I understand that the climate control-radio are one piece. Am I right?

Link to post
Share on other sites

yeah it has a 200 4r. they put them in in 1987 along with Throttle body Injection.

HPIM2224.jpg

Proof from the trans stick.

but right now the caprice is getting 0 MPG

HPIM2221.jpg

Spot anything wrong?

Needs one of these all Im waiting on is a sending unit comes in on friday

HPIM2222.jpg

but to solve your radio problem, heres what i did since the harness will stretch

HPIM2216.jpg

HPIM2217.jpg

Edited by capriceman
Link to post
Share on other sites

Believe it or not, my Suburban got a hair over 18MPG on its last fillup in mixed driving. Not bad for a two-ton school bus with a TBI 350 and a 700R4 with a 3.42 rear end. I wanted a big block when I was originally looking but with the way gas prices went soon after, I'm glad I just got the 350.

I recently stumbled upon a diesel Burb and am seriously considering it. Anybody have any idea what they get?

Link to post
Share on other sites

Capriceman ... I like your radio solution. I may have to do that myself ;).

The choke probably just needs adjusting Cort. Seemed like in those days they adjusted the choke to come off as quickly as possible. Problem is that if you go to far with that kind of thinking it makes the car want to stall while it is warming up. Also make sure your Thermac is working right. If the door in the tube leading to the air cleaner sticks open and doesnt close when its cold it will suck cold air while it is warming up causing it to stumble and also it wont warm up as fast causing poor fuel economy. Just a few things to think about. Another question not related to this, does the 305 in the '76 ping at all or is it pretty quiet. Thats was a horrible problem on the 1979 Impala I had with the 305 and also on Mom and Dads 1978 Impala with that motor. Not a problem on the 1985 Caprice since that has a knock sensor.

No...the '76 doesn't ping at all.

And, the choke has been adjusted...multiple times...lol. I'll check the other again, too, though I know that has been done.... Ya never know, though :).

Link to post
Share on other sites

I wonder if Muntz in Appleton has ever did a stereo that way? I have Circuit City and they have always did me well but Muntz is more specialized in stuff like this. Might be better to let them do it. I dont have a lot in my glove box. I shall have to look at my trans dipstick but I was told mine has the 700-R4 when dad had it rebuilt. Mine also has the 4 barrel carburetor yet which works surrisingly VERY well. Havent had problems with the gas tank or sender yet. I needed a cycling switch for the A/C and the high speed blower relay on mine but that was it. Might see about new spark plugs before it gets cold again. I think now the Bonneville is going to need a high seed relay soon. Had to coax it to work on high. If ever the lower 3 fan speeds with but not high check that. Itsa $10-$12 part.

Edited by 2005 EquinoxLS
Link to post
Share on other sites
  • 3 weeks later...

UPDATING:

I filled all of the MCs up with gas Sunday, August 3...

72 MC "Browny"

...after ~164 miles ... 10.588 gallons ... 15.52 MPG

76 MC "Elvira"

...after ~160 miles ... 10.127 gallons ... 15.86 MPG

79 MC "Sweet Pea"

...after ~179 miles ... 9.502 gallons ... 18.89 MPG

81 MC "Sweet Tea"

...after ~162 miles ... 7.503 gallons ... 21.67 MPG

87 MC "Baby Blue"

...after ~163 miles ... 9.284 gallons ... 17.58 MPG

...previously:

...July 13 ... 18.13 MPG

...July 20 ... 19.36 MPG

...July 20 (after short trip in IL) ... 22.83 MPG

...July 27 ... 17.67 MPG

Cort:34swm."Mr Monte Carlo.Mr Road Trip".pig valve&pacemaker

WRMNshowcase.legos.HO.models.MCs.RTs.CHD = http://www.chevyasylum.com/cort

"I didn't mean to take away your dreams" ... Hootie & The Blowfish ... 'Only Lonely'

Link to post
Share on other sites

Took a road trip this week and went 328 miles on 14 gallons in the stang. Equalls a little more than 23.4 mpg. Not bad at all. Would have done better exept there were a few big pockets of stop and go traffic and crappy road conditions.

Link to post
Share on other sites

'71 Cadillac SDV, (very tired 472 cubic inches) ----> 8.5 MPG (90% city!)

'77 Cadillac CDV (well running 425 cubic inches) ----> 13.5 average MPG (50/50 mix)

'86 Cadillac Fleetwood Brougham [gray/burgundy] (poorly running, tired 307) ----> ~ 16 MPG

'86 Cadillac Fleetwood Brougham [triple silver] (excellent running 307) ----> 18.6 MPG

Just someting to think about.

Link to post
Share on other sites
I recently stumbled upon a diesel Burb and am seriously considering it. Anybody have any idea what they get?

Who cares if you cna do a veggie conversion?! :wink:

Link to post
Share on other sites
Those Panthers really get impressive highway feul economy..need to calculate what it gets in the city next.

Yup... nothing wrong with the Grand Mrq.

Although the B-body was always one step

ahead in terms of fuel economy AND

performance, until GM decided to have

looer elfs from cookie companies run the

show and kill the BOF car as it existed.

Ford's super-parasitic, often-oversized

transmissions are always a crutch... and

yet they still mnaged to be less durable

than GM's smaller TH-variety. go figure.

Link to post
Share on other sites
Yup... nothing wrong with the Grand Mrq.

Although the B-body was always one step

ahead in terms of fuel economy AND

performance, until GM decided to have

looer elfs from cookie companies run the

show and kill the BOF car as it existed.

Ford's super-parasitic, often-oversized

transmissions are always a crutch... and

yet they still mnaged to be less durable

than GM's smaller TH-variety. go figure.

They can do better than 26.6 mpg?

Link to post
Share on other sites

Tunned Port B-bodys in great shape.... (not like my

tired & beat to $hit '92 throttel body injected beast)

are reported to get just a hair over 29 mpg with a

light foot on the highway!

I forget who, but someone on this very forum made

a comment at one point about it.... also I think it

might have been the more aerodynamic wagons.

Either way that is with 1.1 liters MORE than the Ford.

My buddy Kenny has at his dealership, a 4.3 liter

SBC powered 1994 Caprice Classic in immaculate

shape... the car needs NOTHING!

(the little known 267 LT1)

Link to post
Share on other sites
Tunned Port B-bodys in great shape.... (not like my

tired & beat to $hit '92 throttel body injected beast)

are reported to get just a hair over 29 mpg with a

light foot on the highway!

I forget who, but someone on this very forum made

a comment at one point about it.... also I think it

might have been the more aerodynamic wagons.

Either way that is with 1.1 liters MORE than the Ford.

My buddy Kenny has at his dealership, a 4.3 liter

SBC powered 1994 Caprice Classic in immaculate

shape... the car needs NOTHING!

(the little known 267 LT1)

Well FWIW the GM hasn't had a tune-up yet, and I think the front tires are out of balance, so it's certainly possible to squeeze a few more mpgs out.

Either way, for a V8, that's very impressive...it's V6 territory.

Link to post
Share on other sites

My RoadmOnster's 5/7 liter V8, as beat to crap as it is,

turns at just UNDER 2000RPM at 75mph!

4-cylinder $h!box @ 75mph with the motor at 3250rpm is not much better

than a big old honkin V8 turning at much lower RPM....

Link to post
Share on other sites
My RoadmOnster's 5/7 liter V8, as beat to crap as it is,

turns at just UNDER 2000RPM at 75mph!

4-cylinder $h!box @ 75mph with the motor at 3250rpm is not much better

than a big old honkin V8 turning at much lower RPM....

Do let me know when it gets 36 mpg at 75 then.

Also, as I recall it's gearning not cylinder count that determines what a car's RPM is at a given speed.

Edited by Dodgefan
Link to post
Share on other sites
4-cylinder $h!box @ 75mph with the motor at 3250rpm is not much better

than a big old honkin V8 turning at much lower RPM....

This is true...

I'm not quite used to how high the G5 revs in comparison to its bigger OHV Cousins.

Link to post
Share on other sites
  • 1 month later...

UPDATE:

I gassed up all of the MCs on Sunday, August 24 (and may have to do so again fairly soon, given how much I've driven them the last couple weekends)...

"Browny"

...after ~169 miles ... 10.269 gallons ... 16.46 MPG

"Elvira"

...after ~165 miles ... 10.409 gallons ... 15.85 MPG

"Sweet Pea"

...after ~166 miles ... 9.392 gallons ... 17.71 MPG

"Sweet Tea"

...after ~167 miles ... 8.072 gallons ... 20.73 MPG

"Baby Blue"

...after ~159 miles ... 9.377 gallons ... 17.04 MPG

previously:

...August 14 ... 16.92 MPG

...August 17 ... 20.18 MPG

Cort:34swm."Mr Monte Carlo.Mr Road Trip".pig valve&pacemaker

WRMNshowcase.legos.HO.models.MCs.RTs.CHD = http://www.chevyasylum.com/cort

"Does it really matter?" ... Pirates of the Mississippi ... 'Feed Jake'

Link to post
Share on other sites

There you go.... honest to god 20+ mpg out of a respectable

G-body that will put a smile on your face, keep your wallet

fat by avoiding 79% of the Bull$hit repairs that a typical high

milage Civic or Corolla will experience.

BOF-RWD-pushrod.... durable as ANY truck, tough as nails &

comfortable. Def. worth sacrificing 5 or 7 mpgs compared to

most delicate, CV-jointed, rubber timing belted, less safe &

abuse-resistant unibody FWD-ers that size.

Link to post
Share on other sites
There you go.... honest to god 20+ mpg out of a respectable

G-body that will put a smile on your face, keep your wallet

fat by avoiding 79% of the Bull$hit repairs that a typical high

milage Civic or Corolla will experience.

Amen!

Now...if only the MPG was ALWAYS that nice ;)

Link to post
Share on other sites
  • 2 weeks later...

Birthday update:

I gassed up all of the MCs on Friday, September 19....

'72 MC = "Browny"

...after ~195 miles ... 12.385 gallons ... 15.75 MPG

'76 MC = "Elvira"

...after ~190 miles ... 11.466 gallons ... 16.61 MPG

'79 MC = "Sweet Pea"

...after ~192 miles ... 11.466 gallons ... 16.74 MPG

'81 MC = "Sweet Tea"

...after ~191 miles ... 10.003 gallons ... 19.14 MPG

'87 MC = "Baby Blue"

...after ~130 miles ... 9.515 gallons ... 13.70 MPG

previously:

...August 29 ... 15.84 MPG

...September 7 ... 18.66 MPG

...September 13 ... 15.90 MPG

...September 14 ... 24.40 MPG

Cort | 35swm | "Mr Monte Carlo"."Mr Road Trip" | pig valve.pacemaker

WRMNshowcase.legos.HO.models.MCs.RTs.CHD = http://www.chevyasylum.com/cort

"The journey's been etched on your skin" ... James Blunt ... '1973' September 19

Link to post
Share on other sites
Do let me know when it gets 36 mpg at 75 then.

Also, as I recall it's gearning not cylinder count that determines what a car's RPM is at a given speed.

Actually the text you sent me, (I'm reading it as I type this) says:

38.7 mpg

I always thought your milage estimates were all over the map but

gave you the benefit of the doubt, but if you truly believe that

a 1996 Grand marquis averaged 38.7 miles per gallon than you're

just a tad delusional. Or even 36.

Maybe down hill, in neutral on the pikes peek trail, with the AC off.

With all due respect, use your head.

No wonder your Cobalt numbers were so screwy.My parents average

28-31mpg depending on the week/time of year... you said you got

like 15 or 17 or something like that... :blink:

Next time try to drive the car in "DRIVE" not in "L" which stands for

LOW GEAR and is intended for speeds < 20 mph and hill descents. :wink:

Cobalt LS (2.2 liter ecotec) ----> 15 mpg

and

Grand Marquis (4.6 liter modular V8) ----> 38 MPG :scratchchin:

Link to post
Share on other sites

P.S. the Mercedes and RoadMonster both average half of the 38.7 mpg you

claim in your 'Merc, and in the real world, that's not too bad seeing as

both are driven around town quite a bit & both see tripple digit MPH speeds

more often than most people drive over 79mph.

Link to post
Share on other sites
Oh pulease. Every time someone says something that goes against your idea you try to come up with some way to justify how that can't be right (OMG I get 18mpg on a good day so theirs no way you can get 38. The math is wrong, the odometer is suddenly wrong even though the mileage is the same for every trip, a filter in the space time continuum broketified and caused it to happen" or "I'll agree to disagree"

I don't care if your odometer was just calibrated and Stephen Hawkings

did the math, use your head, 38+ mg did NOT really happen in that car.

Link to post
Share on other sites
I don't care if your odometer was just calibrated and Stephen Hawkings

did the math, use your head, 38+ mg did NOT really happen in that car.

i'd have to agree, but... i bet if he was in 4th on a flat stretch (treadmill) going just over the point it shifts into 4th, maybe.

i got ~37 over in indiana..flat..mostly 50 - 65ish....unless the pump lied.

My MC shifts into 4th (while giving it gas) at 39-40 but holds it down to 33, which is kinda irritating sometimes going up hills, which my area has quite a few in some areas in town.

Link to post
Share on other sites

Here's the fleet's numbers

2005 Cobalt: 22 (all city) 2.2L Ecotec

2001 Impala: 25 (all city) 3.8L V6

1976 C-10: 8 (no matter what I'm doing, it gets 8, so range is ALWAYS easy to compute, 8mpg, 21 gallon tank, you do the math) 350 punched .040 over

2003 Alero: 22 (mixed driving) 2.2 Ecotec

1997 Wrangler: 18 (mixed) 2.5 I-4

1992 C1500: 24 (mostly highway) TBI 4.3 V6

2003 S10 crew cab: 26 (mixed) MFI 4.3 V6

1989 S10 Blazer: 24 (mixed) TBI 4.3 V6

1983 C20: 12 (mixed) 4bbl 350cid V8

1966 International Loadstar 1600: 5 (whaddaya expect, its a 2-ton truck with a dump body) 2bbl 304 V8

Link to post
Share on other sites
I don't care if your odometer was just calibrated and Stephen Hawkings

did the math, use your head, 38+ mg did NOT really happen in that car.

Seriously, shut up. I know for a fact that it is correct. We take this route 4 times a week. We've done it in multiple cars. I suppose their odometers are wrong too? Maybe UMass Dartmouth is an imaginary place that doesn't actually exist.

Don't believe me? Fine, piss off then. See if I share any mpg numbers with you again.

Oh and my deepest apologies for the .1 mpg discrepancy. I guess I don't have perfect memory like you.

Edited by Dodgefan
Link to post
Share on other sites

That 38 does seem really high.. I managed to see 27-28 mpg several times in my '87 Mustang GT (5.0) in 5th gear at 55 (back in the days of the 55 mpg speed limit). I've seen on the trip computer instant mileage in the range of 25 before in an '04-07 Grand Marquis rental cars, though.

Link to post
Share on other sites
That 38 does seem really high.. I managed to see 27-28 mpg several times in my '87 Mustang GT (5.0) in 5th gear at 55 (back in the days of the 55 mpg speed limit). I've seen on the trip computer instant mileage in the range of 25 before in an '04-07 Grand Marquis rental cars, though.

It did seem high but that's the number I got that night when we refueled.

But whatever.

Link to post
Share on other sites

I kind of agree with 68 I don't think its possible to get 38 out a GM. In a Prizm, yes. GM no, I think maybe 28-29. The drag alone wouldn't allow it. Im not saying your math is wrong but something isn't right. Use a good map and see how long a stretch of road is and compare that with what your OD says. It might but off or you have too small of tires on it. This happened on the caprice the I had some really bald tires and I went on a road trip and received a mpg of 28 after new tires I did the same trip and averaged 24.5

Link to post
Share on other sites
I kind of agree with 68 I don't think its possible to get 38 out a GM. In a Prizm, yes. GM no, I think maybe 28-29. The drag alone wouldn't allow it. Im not saying your math is wrong but something isn't right. Use a good map and see how long a stretch of road is and compare that with what your OD says. It might but off or you have too small of tires on it. This happened on the caprice the I had some really bald tires and I went on a road trip and received a mpg of 28 after new tires I did the same trip and averaged 24.5

..more rotating mass and actually going faster.

Link to post
Share on other sites
..more rotating mass and actually going faster.

Not sure what you mean by that...

I set cruise at 75 always

But due to the new thread that added about an inch which is 2 more inches in diameter for the tire. The bigger the Tire the longer it takes to to rotate thus the odometer spins slower and speedometer shows a slower speed. How ever a smaller tire will make the wheel spin faster and thus allowing the odometer to spin faster and speedometer to show a faster speed than what the car is going. I hope that clears it up a little.

Link to post
Share on other sites
Not sure what you mean by that...

I set cruise at 75 always

But due to the new thread that added about an inch which is 2 more inches in diameter for the tire. The bigger the Tire the longer it takes to to rotate thus the odometer spins slower and speedometer shows a slower speed. How ever a smaller tire will make the wheel spin faster and thus allowing the odometer to spin faster and speedometer to show a faster speed than what the car is going. I hope that clears it up a little.

i was saying it in response to the "slick" to the new with the mpg. with the slick, yes the odo will be off, but i was saying that with smaller diameter, your car moves slower at any engine rpm vs a larger tire...making it easier for the engine...and the rotating mass of the tire being less. i wasn't factoring in the odo difference. it should be close to just going a little slower... sorta.

Link to post
Share on other sites
That 38 does seem really high.. I managed to see 27-28 mpg several times in my '87 Mustang GT (5.0) in 5th gear at 55 (back in the days of the 55 mpg speed limit). I've seen on the trip computer instant mileage in the range of 25 before in an '04-07 Grand Marquis rental cars, though.

28 mpg in a 5.0 Mustang with a 5-speed trans.? Sure, that's believable.

1. A unibody Fox body Mustang weighs about 1000 or maybe 1200 lbs. LESS than a BOF '90s Grand Marq.

2. '87 Mustang drag coef. < Gr.Marq drag.

3. Top gear (5th) in a 5.0 Mustang is WAY more efficient (lower RPM) than top gear in a FoMoCo automatic 4-speed

D.F. Geez, you seem to be taking my comments a bit personally. :huh:

Back on planet earth, neither Cobalt sedan LS rental cars or gently

used, mid-90s Grand Marq. get the kind of mileage you're claiming.

Link to post
Share on other sites

DF if you're getting 38 MPG out of a 4.6 liter 2 ton boat like a GM and I'm getting under 20 in a V6 powered Riviera....something's not right here and I demand a recount! :angry2:

Edited by Delta Force79
Link to post
Share on other sites
I don't care if your odometer was just calibrated and Stephen Hawkings

did the math, use your head, 38+ mg did NOT really happen in that car.

I'm going to have to second (or like fifth now) that one:

http://www.fueleconomy.gov/Feg/noframes/10122.shtml

Read it and weep, DF:

16 City, 24 Highway, 19 Combined. That's what the manufacturer has filed WITH THE GOVERNMENT as being the car's official fuel economy. There's like a 5% margin of error depending on how much of an old lady you drive like, so best case scenario you're getting high 20's on the highway. And I seriously doubt it because I'll bet a million dollars you had the air conditioning on too.

38? Are you for real? So you mean to tell us that life for a Panther begins at a hundred-plus thousand miles because that's where they hit their sweet spot and DOUBLE their fuel economy? If that's the case then everybody in America needs to drive their vehicles to the junkyard IMMEDIATELY and all pick up a high mileage 15 year-old Crown Victoria/Grand Marquis/Town Car. Congratulations, you've found the answer! Hybrid technology is a sham! America will end its dependence on foreign oil by driving old beat-up Fords!

Here's a hint: don't take what the driver's information center tells you at the second you happen to glance down at it when you let your foot off the gas and coast down a hill as the car's overall fuel economy. If we all went by those figures then my mother's '85 Eldorado was getting 120 MPG..... but only when you were rolling up to a red light.

Link to post
Share on other sites
...everybody in America needs to drive their vehicles to the junkyard IMMEDIATELY and all pick up a high mileage 15 year-old Crown Victoria/Grand Marquis/Town Car. Congratulations, you've found the answer! Hybrid technology is a sham! America will end its dependence on foreign oil by driving old beat-up Fords!

Sweet... i received my $300.00 from the Junkyard for the RoadmOnster

this afternoon and am now styling in my 36.9 mile per gallon 1999 Ford

Interceptor, now if I over-inflate the bald tires, swiss-cheese all of the

non-essential inner sheet metal 1960s Gasser style and mount up some

back-up cameras in lieu of those bulky side view mirrors that rob the

car of several points of drag co.ef I'll be gettin' 40mpg in no time.

I just can't figure out how my old company car, a modern Town Car with

the same (but newer) 4.6 liter V8 only got 18-19mpg on the highway

even though I was driving for a limo company as an airport taxi & HAD to

drive like Mother Theresa for the sake of our rich/pampered clientele.

Link to post
Share on other sites

Both my B-bodies get about 14-16 in town and 23-24 highway. The Bonneville got 26 once but that was once. All the suns must have aligned that day.

Link to post
Share on other sites

Yup.... my beat -to-sh!t RoadmOnster is lucky to average anything above 18mpg.

& that's okay, considering my 2.4 liter I6/5-speed manual Datsun only averaged

22-25mpg being driven in the same manner. I'm okay paying $14 or so more to

keep the Buick fueled up, esp. since (God forbid) if a maniac in a BMW drives into

my B-body it will take the hit much better, and maybe I'll be able to avoid P.T.

and it is a FACT that FoMoCo transmissions are inferior to GM's TurboHydramatics

in terms of durability & fuel economy. Yes a B-bod or two driven by grampa at 55

for 200 miles on smooth highway has gotten 30 mpg... but western mass is not

flat like Florida, where DF was driving.

Link to post
Share on other sites

Considering mine arent as aerodynamic as your Roadmaster and dont have the benefit of fuel injection I would say I do well. I use mid grade fuel in them or the Bonnevilles 307 pings EVER so slightly. Transmissions in both though are from what mechanics tell me, especially the Bonneville pretty lightweight. Mine are both rebuilt though if that has anything to do with it. A/C use doesnt really affect either one.

Link to post
Share on other sites

My spotlights alone must rob the car of 1 mpg....

20080829228fg9.jpg

Link to post
Share on other sites

What are the spotlights for? Here they bust you for having those on a car if it isnt a police car. Hard to believe the Bonneville celebrated its 28th birthday this month. At least the door sticker says September of '80. The 1985 is in December. December of 1984 for that one.

Link to post
Share on other sites

It started as a joke.... they used to ride on top of SpeedingPenguins'

(you might remember him as the guy with the gray/silver '81 Malibu,

although he's never around here) 1988 Jeep Comanche 5-speed.

When he sold the truck he saved a bunch of stuff off of it and left it

in the barn I was renting at the time, later he told me to keep or

sell the stuff and so I said I'd make a 9C1 Roadmaster out of my '92

Buick... they're not swiveling spotlights but most people don't know

the difference anyway.

Of course I didn't expect anyone to really think my B-body with a

waterfall Buick grille is a Chevy Caprice or a cop car in general...

esp with the faded paint and all but since I also installed the larger

push bar style, "kustom, hand machined" bumperettes ($15 worth

of pipe & hardware from Home Depot) you'd be surprised how many

people move right out of the ("fast") passing lane and or yield to me.

Ive even had a few people ask if it was a cop car or ex-cruiser. :rolleyes:

Link to post
Share on other sites

Ok. I just wonder about the weirdest stuff sometimes. Cool car though. I actually thought Buick did a little better with their version of this generation than Chevrolet did. Though I almost did get a 1993 Caprice. Maybe I should have.

Link to post
Share on other sites

Back in high school, 1993-1997, I used to think the Roadmaster sedan was

ugly, with it's narrow, plain, wide tail lights & what seemed to be an angry,

inverted mouth. Now I love those styling features, although I still would

love to own a Impala SS instead but for the money I paid for my '92 B-body

even a base Caprice would have been a steal.

The one thing that turns me off from some of the Roadmaster sedans is the

vinyl , padded 1/4 roof....it's cheesy and ugly & too grandpa for grandpa.

I'm glad I got a steel roof sedan, my old LT1 powered Roadmaster Estate

had more power and much better acceleration but I don't like the very

plain Jane grille on the estates. Oldsmoboi's phantom R-monster was a car

I had envisioned putting together for years! :)

And as far as the spotlights, your question was not stupid...

Link to post
Share on other sites

So there is quite a difference in power between the "old" 350 and the later LT1 350s used in the 1994-96 cars?

Edited by 2005 EquinoxLS
Link to post
Share on other sites

Yes... the LT1 is a more powerful motor.

BUT, not so much so that you should ever not buy a clean, straight '91-'93 B-body. :spin:

Link to post
Share on other sites

I kind of figured. I like the 1993 because they fixed the wheelwells but kept the 1991-1992 dash which I liked better than the 1994-1996 dash. If I did try to ever get one I would try to get a 350. Most though I think had the 305 just like the 1985 but with fuel injection. Still like FWD or AWD though for winter.

Link to post
Share on other sites

RWD is the safest driveline for winter.

All cars skid over black ice and stop with all four wheels.

Now as far as Caprice Classics, by the last gen. B-body

most of them were 350-powered although I was recently

tempted by 267 (4.3 liter SBC V8) economy Caprice that

was for sale at a buddy's used car lot.

Link to post
Share on other sites

OK....so back to fuel economy......

Drove a 2008 Escalade from Las Vegas down to Phoenix to deliver to a customer.........all freeway miles.......14.1mpg.

<ouch>

Now granted, the cruise was set at 85mph, and I had plenty of passing maneuvers in the mountains with my foot buried into the floorboard........(on the other hand, I've heard of 20mpg easily in the Escalade at a more relaxed 70-75mph cruise on a freeway stint....)

Link to post
Share on other sites

It's an Escalade, no shame at all getting 14mpg in a 6+ foot tall BOF Cadillac with a

honkin V8 and curb weight & luxury appointments that put Rolls Royce to shame.

BTW; here's a better pic. of those spotlights:

2008081625050wo2.jpg

Link to post
Share on other sites
The Balt is up to 27.2 MPGs...about time!

mostly city? mostly highway? mix?

Link to post
Share on other sites
RWD is the safest driveline for winter.

Remember I have driven RWD in winter quite a lot. But to each his own. Though the B-bodies are about the safest RWD winter vehicle there is based on my expeirience.

All cars skid over black ice and stop with all four wheels. True that.

Now as far as Caprice Classics, by the last gen. B-body

most of them were 350-powered although I was recently

tempted by 267 (4.3 liter SBC V8) economy Caprice that

was for sale at a buddy's used car lot.

Saw one of those too a little while back. There are actually more box B-bodies (1977-1990) than the later ones here. People didnt seem to like the 1991-1996 very much including my dad.

Link to post
Share on other sites

yeah.... I see their point too, I really love the '91-'96 Roadmasters but there's

something really cool about a '90 caprice with the flush mounted Headlights &

yet the BIG heavy chrome bumpers front and rear. :)

Link to post
Share on other sites
yeah.... I see their point too, I really love the '91-'96 Roadmasters but there's

something really cool about a '90 caprice with the flush mounted Headlights &

yet the BIG heavy chrome bumpers front and rear. :)

Damn straight. I think Dad would have traded the 1985 for a 1990 if one would have became available. But it never did. No matter. I love the 1985 to death. And the 1981. post-475-1223194961_thumb.jpg

Link to post
Share on other sites

That's a really nice Bonneville; why did I think it was a two-door? Did you ever have an older two-door car that you've mentioned here? I really could have sworn it was a two-door.

Link to post
Share on other sites

Dude, I'm quite shocked that you have not shown off this fine

Pontiac yet in the "members rides" forum. Not that I expected

it to be a beat up pile but that thing is gorgeous. :wub:

Link to post
Share on other sites