dwightlooi

Final Drive: 2.89 1st : 4.584 (35mph @ 6500 rpm) 2nd : 2.964 (54mph @ 6500 rpm) 3rd : 1.912 (84mph @ 6500 rpm) 4th : 1.446 (111mph @ 6500 rpm*) 5th : 1.000 (161mph @ 6500 rpm*) 6th : 0.746 (216mph @ 6500 rpm*) * Theoretical; the car is electronically governed to 103 mph Here are the corresponding rpms at 75 mph 1st : N/A 2nd : N/A 3rd : 75mph @ 5804 rpm 4th : 75mph @ 4392 rpm 5th : 75mph @ 3028 rpm 6th : 75mph @ 2257 rpm No, these ratios and final drive numbers are for the Cruze with the 6T40 Automatic. If all the Cruzes are NOT shifting into 6th... I think GM has a BIG problem. http://archives.media.gm.com/us/powertrain/en/product_services/2010/gmna/Spec%20Sheet/Transmissions/2010%20Automatics/10_6T40_MH8_n.xls

There is something VERY WRONG here. If they are seeing 3,000 rpm at 75mph, I am pretty sure they are in 5th instead of 6th gear. This means that either the tranny is broken and won't shift into 6th or they put it in fifth manually and are seeing lousy mileage because of that. Here's the gear ratio of the Cruze 1.4T with a 6T40 automatic transmission -- per GM's specs. Final Drive: 2.89 1st : 4.584 (35mph @ 6500 rpm) 2nd : 2.964 (54mph @ 6500 rpm) 3rd : 1.912 (84mph @ 6500 rpm) 4th : 1.446 (111mph @ 6500 rpm*) 5th : 1.000 (161mph @ 6500 rpm*) 6th : 0.746 (216mph @ 6500 rpm*) * Theoretical; the car is electronically governed to 103 mph Here are the corresponding rpms at 75 mph 1st : N/A 2nd : N/A 3rd : 75mph @ 5804 rpm 4th : 75mph @ 4392 rpm 5th : 75mph @ 3028 rpm 6th : 75mph @ 2257 rpm Hence, ~3000 rpm at ~75mph is most definitely in 5th.

Uh... except the 1.4T is not available in Europe. The Europeans get a 1.6 and a 1.8 NA four, plus a 2.0 Turbodiesel. The 2.0 Turbodiesel is actually the highest performance motor for the Cruze at 150hp / 240 lb-ft

IMHO,k the Camaro is and always will be a muscle car. That's its image, and that's its selling point. In that regard a 3.6 V6 is probably a better engine for the base car than an I4-turbo. As far as fuel economy goes, a variable duration valve train on the V6 will essentially equal the current breed of Inline-4 turbos. There is also no need to go over board on the MPG thing in the Camaro. CAFE will be won or lost in the Sonics, Cruzes and Malibus, the Camaro just have to be mid-pack, it doesn't have to be a leader on the GM's MPG chart. Also, it is not a big deal if GM misses CAFE. It is not the end of the world and the fine is quite minuscule per vehicle. If you miss by a full point, that's $40~$50 per car. Nobody will notice that that in the price tag.... just pass it along. It is more important to build cars that the market wants rather than cars that help nudge the CAFE rating up a few tenths of a point. Now, if Chevy wants to build a "modern" sports coupe. They can build a 2800 lbs 2-seat, mid engine, scissor door $25,000 coupe with a 300hp Turbo-4. It'll probably be well received too. But they shouldn't call it a Camaro. Calling it a Camaro actually hurts from a marketing standpoint because the "Muscle Car" buyer won't like the car and the "Techno Coupe" buyer won't like the name!

The 1.4 is not cheaper than a 2.0, the turbos cost about the same. The only difference would be DI. That's a maybe $200~300. Besides, the cost on the 1.8 base model would not have changed. The upscale car can probably tolerate a $500 price hike for being best in class

I have never been a fan of downsizing displacement as the primary means of attain fuel economy goals... primarily because it doesn't really work and other solutions are more effective. They could have simply taken the LNF DI Turbo engine, switch to Miller Cycle* cams, and a smaller turbo. This would have produced an engine with equal economy to the 1.4T and more power -- probably around 170 bhp / 170 lb-ft. Now that would be more appealing as an "upgrade" engine over the 1.8. Not only will it have better MPG numbers, it'll also be more powerful and will put the Cruze ahead of the pack in performance as well as fuel economy. * Miller Cycle is basically Atkinson Cycle with forced induction added. The intake valves close very late into the compression stroke reducing the effective displacement of the engine (by 20~30%). This also creates a virtual asymmetric compression and power stroke -- the later being effectively longer -- which promotes superior energy conversion efficiency.

(1) A turbo and its intercooler is about $500 (assuming GM sources them at 1/3 what you would have paid on the aftermarket). A DI system is less than that for sure. A high compression DI 1.8 with part-time Atkinson (ala Civic's R18) would be similarly efficient as a low compression 1.4 turbo at a lower cost. The 1.4 turbo will however have more torque and a more accessible torque curve. A 1.4 turbo will also be more "special" from a differentiation standpoint. (2) An 2.0 I4 with AWD is about the same weight as a 6.2 V8 with RWD. The center diff, front diff and half-shafts are roughly the weight difference between the V8 and I4. The Turbo-4 AWD will launch better. The V8 will have better power to weight ratio.

To put it simply, I'll simply quote GM's powertrain engineer Dave Sczomak (GM Powertrain Advanced Engineering) "Well north of 450hp". To put it another way... The LS3 engine makes 426hp on 10.7:1 compression without a loud exhaust or lumpy idle. DI will raise compression by at least 1 point to 11.7:1. With no changes in any other areas, a 9.3% increase in compression is worth roughly a similar amount in hp & torque increases. This equates to about 473 hp. Remember, that's compression increase without adding VVT, improving airflow, reducing friction or anything else -- which is highly unlikely. My guess is that Gen V 6.2 is a 450~500hp engine. In the lower half of that range on the ATS-V due to noise and refinement concerns, in the upper half of that range for the brasher Vette.

About 20~23 City, 30~35 Hwy assuming the aerodynamics is not horrible. A lot of it depends on the selection of the final drive ratio. It also depends on whether GM will put in new technology like continuously variable lift & duration (which essentially gives you variable compression).

The engine may be will most likely be a 2.0 or 2.4 based on a Gen III Ecotec. Possibly fortified with a turbocharger. But it wouldn't be an LNF. The Gen 6 Camaro is NOT around the corner; it is 3~4 years away. The LNF will be 10 years old by then. Hey maybe it'll even be a 3.1 liter pushrod which is actually a pretty neat idea if you don't mind a little roughness that seeps through the twin balancers. Here are the possible contenders:- 2.0 Ecotec3 DOHC-16v DI-VVT Turbo (High Boost; ~ 20 psi) Bore x Stroke: 86 x 86 mm Displacement: 1998 cc Compression: ~9.7:1 (est) Power: ~300 @ 6000 rpm Torque: ~270 @ 2800~5800 rpm Fuel: 91 Octane 2.4 Ecotec3 DOHC-16v DI-VVT Turbo (Low Boost; ~ 13 psi) Bore x Stroke: 86 x 86 mm Displacement: 1998 cc Compression: ~9.7:1 (est) Power: ~300 @ 6000 rpm Torque: ~270 @ 1800~5800 rpm Fuel: 87 Octane 3.1 Gen V Pushrod-8v DI-VVT Turbo (Very Low Boost; ~ 9 psi) Bore x Stroke: 103.25 x 92 mm Displacement: 3081 cc Compression: ~9.7:1 (est) Power: ~270 @ 5000 rpm Torque: ~300 @ 1600~4600 rpm Fuel: 87 Octane

The Vettes and Vs do not matter much in terms of CAFE. GM sells about 25 million vehicles. Vs and Vettes don't add up to 40000 even on in the best year. That's 0.16% of the total volume, besides Corvette MPG numbers are actually pretty good at 16 city /26 hwy. As far as small fraction of that which are the ZR1s and CTS-Vs... well... they can be average 1 mpg and it won't nudge GM's CAFE numbers by 0.1 (the smallest granularity the feds register for the purpose of collecting the CAFE tax).

Well, it is actually easier with turbocharged engines to make premium optional... Pinging and knocking, despite what a lot of people think, typically doesn't manifest themselves first or as severely at high rpm, maximum power situations. They manifest themselves first and most disturbingly at low rpm, high load situations. The reason being that pinging and knocking are basically spontaneous conflagrations within the cylinders before the spark fires or before the flame front from the spark ignited combustion reaches the edges of the combustion chamber. One way to think of it is that every firing of a cylinder is a race between the spark initiated flame front and self-initiated flame front from some hot spot within that cylinder. If the spark front wins you have a smooth combustion, if the hot spot front wins you ping. If the latter wins big, you get a knock! While rpms may vary, the flame fronts travel at the same speed. Hence, when the engine is hauling a significant load at low speeds with a wide open throttle, you have the maximum charge density and the maximum amount of time for the ping or knock to actually happen. There isn't very much you can do about it in a naturally aspirated engine because the compression ratio is what it is. And at a given engine speed and load, the engine will suck in a given amount of air and squish it to a given degree. The most you can do is play with the spark timing and enriching the fuel mixture (which lowers the combustion temperatures and serve to retard the knocking). In a turbocharged engine, the charge density is a combination of static compression and compression of the intake air charge by the turbocharger. The static compression ratio is usually quite low; about 1~3 points lower than the naturally aspirated version of the same engine. The engine is not going to ping or knock easily at such compressions ratios if there is no boost or very little boost. And, because modern engines have the ECU directly controlling the wastegate solenoid, they can directly control the amount of boost being applied in any situation. Hence, it is pretty easy to tune an engine for high performance with Premium Gas, yet accommodate Regular Gas by trimming down boost pressure the moment mild pinging is detected. Sure the engine may perhaps lose 50 hp in the process. But... it won't blow up.

I get 25.2 mpg at 65 mph (constant speed over 30~35 miles) in the C55's 5.5L M113 V8 (SOHC 24v). The car actually has a pretty short cruising gear -- 2350 rpm @ 65 mph, 2900 rpm @ 80 mph in 5th. So, almost halving the displacement and dropping two cylinders got you 2 mpg. Well... I am sure the MKZ is also not 3600 lbs and AWD probably costs about 5% in fuel efficiency. Still... if you are after fuel economy the top priority shouldn't be downsizing the engine, it should be weight, ratio spread, aerodynamics, cylinder count then displacement. Displacement being a distant fifth on the list.

Honestly, I believe that if GM does a 3.0TT it'll be a low boost application similar to the BMW 335's 3.0T. I say that for two reasons... firstly, GM is probably not looking for a hot rod engine but a replacement for the 5.3 LS4 engine. Secondly, I suspect it'll be introduced soon with today's transmissions. To that end, the 6L50 and 6T75 medium torque automatic have torque ratings of 332 and 300 lb-ft respectively. There is no step up for transverse/FWD applications and I am presuming that they'll want to use the engine in things like the SRX, ETX or Lacrosse. Such an engine will probably focus on extremely responsive power delivery, good fuel economy (meaning high compressions) and possibly 87 octane compatibility. Spec wise... Type: 60 degree V-6 Aluminum Block & Heads DOHC-24v w/ independent intake & exhaust VVT Displacement: 2997 cc Bore x Stroke: 89 x 80.3 mm Compression Ratio: 10.7:1 Aspiration: Twin Turbocharged and aftercooled 2 x Honeywell-Garrett MGT20 turbochargers 10.3 psi Maximum Boost Horsepower: 320 bhp @ 5600 rpm Torque: 300 lb-ft @ 1600~5600 rpm Redline / limiter: 5600 / 6000 rpm Fuel Injection: Direct Gasoline Injection Fuel Type: Regular 87 Octane (Recommended) If they make a high boost version for the ATS-V or Corvette or some other performance car, they'll drop compression, crank up the boost and use bigger turbos. The engine will also probably be tailored to fit within the envelop of the 6L80 transmission Type: 60 degree V-6 Aluminum Block & Heads DOHC-24v w/ independent intake & exhaust VVT Displacement: 2997 cc Bore x Stroke: 89 x 80.3 mm Compression Ratio: 9.2:1 Aspiration: Twin Turbocharged and aftercooled 2 x Honeywell-Garrett MGT22 turbochargers 19 psi Maximum Boost Horsepower: 430 bhp @ 5300 rpm Torque: 430 lb-ft @ 2200~5200 rpm Redline / limiter: 5300 / 6000 rpm Fuel Injection: Direct Gasoline Injection Fuel Type: Premium 91 Octane (Recommended)

Well, the predictions are just that... predictions. You can come back in 3 years and say I am right on target or I am shooting in the wrong direction. But that's all its worth. I wish people won't misrepresent fictional predictions as fact. Having said that, the numbers -- IMHO -- ought be pretty good guesses. FACT: In 2007 GM modified the L92 (Vortec 6200) 6.2 V8 to operate using direct injection. The engine was running smoothly in an Escalade. That engine had 11.5:1 compression (a 1 point bump over the L92) and was making "well north of 450hp" as opposed to 403 hp in the original port injected configuration. PREDICTION: A 6.2 V8 designed from the ground up to use DI, uses slightly higher compression, benefits from airflow optimizations at least equivalent to the LS3 and with variable timing added will also make "more than 450hp". How much more? 20hp is not an unreasonable guess.

That's why you put a DOHC Direct Injection Variable Timing Twin Scroll Turbo 2.0T as the base engine and a 92 bhp / liter V6 as the mainstream upgrade. The ATS-V is always going to be a niche product. GM will be lucky if 5~10% of ATSes sold is a V. As far as niche products go, being alone in the crowd with a 6.2 badge is not necessarily a bad thing. It's differentiation even if it is not inline with the majority perception. Even if it appeals to just 20% of the potential buyers and turns off 80%, that's 20% you don't have to share with Alfa, Audi, BMW, Lexus, Mercedes, Volvo or anyone else.

It does add about 100 lbs of weight and take a whack out of trunk space.

Actually, I don't think that's the root of the problem. The root of the problem was that for decades GM -- and most US automakers for that matter -- did not realize one fundamental fact: "The USA is a high cost country. You don't succeed as a business operating in a high cost country by trying to be the value leader." GM had always tried to sell their cars for a few hundred to a few tens of thousands less than the competition. This means that they need to cut quality, cut material grades, cut technology and cut all kinds of things to get to the price point. This created a perception -- much of it grounded in fact -- that GM equals low quality and low tech. Designs associated with GM such as the Pushrod small block garnered the same kind of associations, justly on unjustly. At the end of the day it's a no win situation. Despite all the bean counting and discounting, the difference between US labor costs and, first, Japanese, then Korean and now Chinese, cannot be overcome. GM gets stuck with inferior products compared to the European "prestige & quality" leaders. They are also no cheaper and often still worse off in technology, quality and features compared to Asian imports. I think they realize that now... or at least I hope they do.

The reality is that despite the fact that people moan and bitch about it, fuel expenditures really aren't that big of a deal despite gasoline prices having tripled in the last 15 years. I drive about 12500 miles a year. I get ~18.5 miles a gallon in the C55. That's $2,365 a year at $3.50 a gallon. If I have a Camry or Accord V6 and pull in an average of about 24 mpg in combined driving -- a good 30% improvement in fuel economy -- the same driving habits will cost $1,823 a year. That's a difference of $542 a year or $45 a month. $45 is not even enough for a dinner for two. In the 90s, it's $70 vs $52. Today, it's $200 vs $150. That's three times, but it's also not a big deal either way. In general, people who explicitly sink $60~80K on a performance car is not going to care very much about whether they are out $200 or $150 on gas every month. On the same token, if a $5000 Hybrid system can get me from 18.5 to 24 mpg in with the same performance, they probably don't care for it if they can do the math because it'll take them over 9 years just to break even on the investment -- just in time for a $2000 battery replacement! Unless... they believe in the fraud of the century called Global Warming.

Actually, the converse is true. A pushrod engine is significantly lighter and smaller than a DOHC engine. If you take a DOHC V8, throw away three of the four camshafts, their sprockets, their bearings, halve the number of valves and make the cylinder heads about 1/3 the size... you'll arrive roughly where a Pushrod V8 is in terms of size and weight. In fact, the difference is so pronounced that a 6.2 liter Pushrod V8 is typically lighter than a 4.0 liter DOHC V8. Eg. The BMW S65 4.0 V8 engine in the M3 is 202 kg, whereas LS3 6.2 V8 in the Corvette is 183 kg.

(1) A 5.5 does not offer substantially better fuel economy than a 6.2. With the same amount of valvetrain friction and a mere 11% reduction in swept volume efficiency gains are in the 1~3% range. This may not even get you to the next 1 MPG. A 5.5 is about 420hp at the same specific output. The engine will be no smaller and no lighter. Hence, it is probably best to maximize the advantage of the pushrod engine -- which is the ability to deliver the highest power density from the smallest engine dimensions and weight. (2) GM will probably add a diesel or two for Europe. It'll be something taken from the Open portfoilio. Probably a 4-potter at 180~220 hp and a V6 at 250~270hp.

There are two reasons:- (1) The V6 has higher specific consumption, so it needs a lower cruising speed more than the Turbo-4. Also, it can probably tolerate a taller cruising ratio than the the 2.0 liter four while crusing along off boost on the freeway. (2) The final drives ratios are selected to "game" the system and provide the best 0-60 mph and 0-100 km/h (0-62 mph) numbers for the magazines... I wanted either one shift or two shifts to 60 mph. The V6 gets to 62 mph in 2nd. With the turbo-4 it gets there in 3rd. In either case, they reach 0-60 right before the next shift.

Well... 2014 model year = introduction in August 2013. Somehow I doubt they are far along enough to introduce it August of next year or we'll be seeing spy shots of the real thing running around by now. GM was working on the 8-speed when the whole bankruptcy business unfolded. It got put on ice. Not sure if it got restarted. But if it does, the 2014 model year is right where we may see the first ones. They'll probably introduce the 8-speed boxes over a period of 2~3 years rather than all at once. The logical thing to do will be to introduce it for the 220~300 lb-ft applications (that of the mainstream V6es) first -- the big V8s can make do with 6-gears and taller gearing for fuel economy, the econoboxes segment is probaby too price sensitive to splurge on 2 additional gears for another grand. This is why I kept the V-ship as a 6-speed.

Edit: Due to the high influx of visitors, I must add this disclaimer: Contrary to what some media outlets have reported, this is not a leaked GM document. This is scientific speculation based on what we know about GM engines and other technologies GM has been working on. Simply put we are hypothesizing about what the power output of a 6.2 liter would be if direct injection was added for example. - DD

Well... Alpha will be the litmus test... if GM is able to make good headway in weight control it'll start with Alpha. If Alpha weighs in at 3800 lbs we'll know that GM is either not particularly serious about weight discipline or are incapable of it. Alpha needs to come in at no more than 3400 lbs for a lightly optioned car with a 4-cylinder engine, about 3600 lbs for a well equipped V6 and no more than 3700 lbs for an ATS-V with a small block V8. That's not really an ambitious target... it's about a 250 lbs savings over a comparably equipped Zeta and about on par with an E90 3-series. Perhaps GM can do better, but an Alpha at such weights this will be "good enough". It's actually not that hard. A unibody with high strength steel at the crucial locations, a cast light alloy cross beam and hydro-formed sub-frame is worth about 100 lbs. Laser seam welding and thinner gauge material overall with 2-ply butting is good for another ~100lbs. Throw in a aluminum hood and roof panel and you are basically there. GM has a few traditional advantages too. For instance, with GM's engines, big power is relatively light. Eg, BMW claimed that the 4.0 liter S65 V8 is the lightest mass production DOHC V8 in the world. That may be true. But at 202kg, it is heavy compared to the 183kg LS3 which makes 22 more hp and 133 lb-ft more torque.