dwightlooi

Well, first of all, big V8s and supercharged motors do not necessarily have to be behind on technology or refinement. In fact, if you compare today's GM Pushrod 6.2 V8s with most DOHC V8s in the 4.6~5.5 liter class, they are neither less refined nor inferior in performance or fuel economy. The next generation will bring with it Direct Injection, Variable timing and cylinder deactivation -- all the technological goodies that some DOHC engines enjoy over the current crop of Smallblock V8s. An interesting development will be a reverse flow Pushrod V8 with a single turbo nestled in the valley of the engine. This is interesting for two reasons. The first being that a single large turbo is more efficient than two smaller ones. The second being that it is also cheaper, as well as neater in terms of intercooler and intake plumbing. Such as engine, using a state of the art turbo like the ball-bearing Honeywell-Garrett GTX3582R will be capable of about 650 hp @ 6200 rpm along with an extremely linear 550lb-ft @ 2200~6200 rpm torque band.

Maybe GM will offer BMW the superior power-to-weight ratio, improved power-to-size ratio and enhanced fuel economy of the Gen V Pushrod V8 for their M-cars... LOL. But, seriously, a GM BMW alliance makes sense. BMW had been using GM 6-speed automatics for the AWD variants of their 3, 5 and X series, and has no in house automatic transmission capability. GM also has the Voltec drive train, as well as various dual-mode and mild hybrid tech. BMW on the other hand has made serious investments in Diesels -- an area GM is seriously deficient on. More importantly, BMW does not see GM as a competitor and vice versa. Everything except Cadillac operates in a different segment than anything BMW does. Cadillac itself is such a minor presence in Europe and internationally that it is no threat in immediate future.

Here's the official one straight from GM Powertrain If you have an LUJ, here answers to some questions you may want to ask... What kind of turbo is in the 1.4T engine (LUJ/LUV)? The Turbo is a Garrett MGT14 (MGT1446 to be precise). It is most similar to a Garrett GT15 if you want a generic reference. The "M" in front of the model designation indicate that the turbocharger's turbine housing is a custom casting that is one with the exhaust manifold. The "46" indicates that it has a 46mm compressor wheel which is between that of a GT1544 (43.9mm) and a GT1548 (48mm). This turbocharger can support up to ~175hp in airflow before falling off the map and becoming highly inefficient. How much boost does it run? The Stock Boost level is about 12.8 psi on a static compression ratio of 9.5:1 How much boost can be run if the ECU is reprogrammed? You can probably run about 15 psi on regular 87 octane and about 18 psi on premium 91 octane on the 9.5:1 stock compression. How much power can the engine make? On 87 Octane, using 15 psi of boost an estimated 150hp @ 5000 rpm and 165 lb-ft @ 2500 rpm can be made on stock compression. On 91 Octane, I estimate 175hp @ 5000 rpm and 180 lb-ft @ 3000 rpm. In all cases, peak torque will arrive later and the engine will be somewhat less linear, although probably not objectionably so. Will a new intake, filter or exhaust help make more power? The biggest issue is the intake manifold. GM has molded into the intake a set of tumbler dams* just ahead of the intake ports. These obstruct the lower 1/3 of the intake ports creating a tumbling effect on the inducted air. This is good for emissions, probably in an effort to get it to ULEV or some preferred rating. They can be removed if you pull the intake, then Dremel and sand paper them out. Removing the dams is worth about 5~7% more torque across the board, assuming ECU is retuned to account for the increase in volumetric efficiency. How fast will a Cruze be if you run 18 psi and do the intake runner mod? About 7.0 secs to 60 mph. *Tumbler Dams

Today, Ford's Ecoboost 3.5 V6 has a 1 mpg advantage over the 5.3 GM V8. It also has higher output. However, with the addition of direct injection, cylinder deactivation, variable timing and approximately 1 point increase in compression ratio in the Gen V pushrod V8s, it is not unreasonable to expect no less than 1~2 mpg improvement from the V8 along with 72~76 hp/liter. This allows the V8 to match or exceed the performance and fuel economy of today's Ecoboost 3.5 V6 without the cost, complexity and bulk of two turbo chargers, intercoolers and a pasta bowl worth of plumbing, not three more camshafts and 50% more valve train parts. Back to my original point... what it means is that going to a small displacement, twin turbo V6, is NOT the only competitive way forward for GM trucks.

I have never said that "Trubo engines are all crap like they used to be". You said that. What I said was that Turbocharged engines had, have and will continue to have, higher maintenance requirements and more points of failure than Normally Aspirated engines. This is not to mention higher production costs. I also do not believe that the overwhelming majority of vehicle buyers will buy a vehicle with a turbocharged engine for the sake of it being turbocharged. I'll say the same about alphabet soups like DOHC or whatever. I honestly do not believe that any of these matter to the majority of car buyers. In fact, most wouldn't even know what these things stand for or how they work. This is especially not the case with truck buyers. I believe that what's important is hitting or exceeding the performance, refinement and fuel economy targets. In this regard, when it comes to light trucks, a direct injected pushrod V8 is a fully viable, competitive and economical alternative to a twin turbo V6. Fully viable in that GM knows how to do it. Fully competitive in that it can match or exceed the ecoboost engine on performance, refinement and/or fuel economy. Economical in that it is a lower cost solution. I believe that consumers will judge the vehicle and its engine on their merits. In fact, I do not believe that there exist a prevalent perception that turbocharged engines are desirable for the sake of the fact that it is smaller displacement and turbocharged.

True that it's an AMG derivative. They use it with the 5.5 Biturbo also. I haven't seen anything that says that when you get the AMG Performance Pack (and 664 lb-ft), you have to take the 5G-TRONIC with it. I guess my point was that even though they have this transmission that could at least handle the torque produced by the V12 in the S600/CL600, it's more than likely not a mass-producible unit. Back to Cadillac... if they indeed build a V12 by mating two V6s end-to-end, what are the prospects of them somehow finding a way for the Omega car to mate the V12 with AWD? BMW and Mercedes haven't yet, and Audi got around it by building the W12. It would be huge, I think, if Cadillac could engineer that in. It's really more of a height issue. You need to have the front differential fit under the engine. You can do this by raising the engine higher (which has hoodline and Cg impacts) or trying to fit that front diff through the oil pan. Some designs will use an oil pan with a front and rear reservoir and raised center section in the middle. More integrated will be a customized front differential casting that is also the oil pan itself. That, plus a little foot well space encroachment from the transfer case and shaft. Also, about 150~200 lbs more weight to the vehicle. BMW actually uses GM Hydramatic 6-spd autos for their AWD cars.

Actually, no. I know that turbo technology have not changed much over the last 5~8 years when it comes to reliability enhancing breakthroughs. Can you name ONE new feature on the turbo used in the LNF or LHU engines that isn't around at the turn of the millenium? No, you can't because there is none. The biggest improvement in turbo life came with the water cooled bearing section. That was over 30 years ago. Next came the after run water circulation pump. All the VWs from the late 90s had that. And, before that using a turbo timer to keep the engine running for a few minutes after the key is out has a similar effect of preventing stationary oil coking on red hot turbo bearings after a hard run. Sodium filled valve stems do nothing to extend oil life. Nada, zero, zilch. What they do is help cool the exhaust valves better and prevent hot spots on them that may cause engine knocks or weaken the valves. BTW, Eaton did not make the LNF turbocharger. The Turbo in the LNF engine (Solstice GXP / Cobalt SS) is a KKK K04 unit. It has the same reliability enhancing features -- a water cooled bearing jacket and an after shutdown electric coolant pump -- as a 1998 Passat 1.8T (which is a smaller but otherwise similar KKK K03). If you obey the oil life monitor, you'll probably get between 5000~7000 miles out of your Mobil 1 fill. At least that is what many owners are getting. The Malibu's 2.4 gets almost twice that (9,000~13,000). You can't say that that constitutes no difference. That may not bother you and it may be similar to an older car you drove, but it is significantly worse than the 10,000~15,000 mile oil change interval NA engines can get out of the same oil today. The whole oil thing aside, you CANNOT argue that pressurized plumbing leaks, intercooler leaks, Bypass valve diaphragm failures, wastegate solenoid faults, thrust bearing failures, turbo oil seal leaks and a host of force induction paraphernalia failure is POSSIBLE on an NA engine. You cannot because stuff that do not exist cannot fail.

Really? How about the fact that every turbo I have had -- and I have had quite a number from a Talon TSi (Eclipse GSX), New Beetle 1.8T, Celica All-Trac Turbo and Audi S4 -- have shorter oil change intervals than their non-turbo counterparts. In addition, I have had several instances of leaking intercooler plumbing or end tanks and one instance of a bad waste gate solenoid valve. None of the cars were over 11 years old or had more than 115K miles, the average age was ~8 years when at the end of my ownership experience. Again... nothing catastrophic, nothing partcularly bothersome, but all of these are failure points which an NA engine DOES NOT have. In short, a turbocharged engine has ALL the failure modes an NA engine has, plus additional ones. That is not a debatable notion, it is a fact. A turbocharged engine, by virtue of the high temperatures in the turbine bearings, also have more demanding oil requirements or more frequent change intervals or both. These are also not debatable.

First of all it is pretty hard to argue with hard MPG numbers, so the whole perception thing is an illusion does not survive even a cursory reference to the window sticker. It is probably a harder sell convincing buyers that twin turbos will not cost more to maintain and will be as reliable 10 years down the line, than it is so point to the window sticker and say that your V8 is just as economical than their V6 or more so. Secondly, I don't believe that truck buyers in general fall into the "early adopters of technology for technology's sake" crowd. What makes you so sure that the 40% of F-150 buyers who bought the Ecoboost engine bought it because its twin turbo and "high tech", rather than the fact that it is 5hp more powerful and 40 lb-ft more torquey than Ford's 5.0 V8?

First of all, I don't think GM is putting a "similar" engine in the upcoming Silverado -- similar as in V6 twin-turbo. What will probably happen is that GM will keep the V8, keep the pushrods and keep the larger displacement over the Ford Twin-Turbo 3.5 V6. However, the new Gen 5 Smallblock V8 will feature Direct Injection, cylinder deactivation and variable valve timing. The target of course it to match or exceed the Ford turbo V6 both in terms of performance and in terms of fuel economy without the cost and maintenance disadvantageous of the Ecoboost engine. Given that even the current port injected V8 is only 1 mpg off, this is a very achievable target. If they keep the 5.3 liter displacement, expect about 400 hp / 400 lb-ft from a direct injected small block with mpg numbers about 1 mpg better than the Ecoboost 3.5 just from AFM and higher compression alone. If they really want, they can milk another 1 mpg out of it by going to a taller axle ratio which the increased torque output will allow with no degradation in acceleration or tow rating. If they are smart, they will make a large displacement pushrod V6 (approximately 4.7 liters) with a similar output as today's 5.3 V8 (~300 hp / 300 lb-ft). Such an engine will be both cheaper, easier to maintain and more economical than a boosted 3.5. This may also make a good engine for the Caprice for instance when the Police department or some other fleet buyer will rather have a lower cost engine with better economy than the V8.

The AMG speedshift is actuallu a derivative of the 7G-tronic. What they did was ditch the torque converter for a electro-hydraulically controlled clutch. In otherwords, its a planetary automatic with a computer controlled clutch instead of a torque converter. There was some degradation in smoothness, but the torque rating was higher and the shifts are much faster and sharper. This "clutched" 7-speed is used with the 6.3 NA V8, but the V12 Bi-turbo continues to be paired with the 5-speed traditional automatic because of torque rating issues.

Well, for a given transmission design and case volume, there is generally an inverse relationship between torque rating and the number of speeds. The reason is simple, high torque ratings require fewer wider gears and more speeds require more skinnier gears. To get both you enlarge the transmission. Also, it is important to note that BOTH increase the parasitic loss of a transmission all else being constant. Wider gears or more skinnier gears increase frictional drag -- even when they are free spinning and unengaged. The most efficient transmission at ONE any given ratio is one with the fewest and narrowest gears. If you start at 60mph and crusie at 60mph, a 1-speed transmission with just enough torque loading to handle the engine's output at 20% throttle will beat any 8-speed tranny capable of monster torque inputs hands down. The challenge of course is striking a compromise between getting enough torque capacity to handle the output of a given engine and having enough gears such that you get good acceleration performance on the way to your ideal crusing gear (which is usually quite tall). The thing here is that lots of speeds are not necessarily necessary to maximize performance or economy. You see, when you have 550 lb-ft and two road going tires, there is only so much torque you can put down in 1st before you create zero improvement in acceleration just a lot of burnt rubber. In otherwords, with enough torque you can simply select an axle ratio that gives you 1200 rpms at 65mph and simply live with the fact that 1st gear will be quite tall as well. In fact, this may not actually hurt acceleration at all given the traction limits of two tires of reasonable widths. What I am trying to say is not that 8-speed transmission are useless. What I am saying is that they are much more useful in lower torque powerplants with narrow power bands than they are for a monster V12 or even a big Supercharged V8. Engines like the 2.5 liter 4-cylinder in the Malibu or the 3.6 V6 will benefit from 2 extra gears much more so than the CTS-V or V12 Omega.

Actually it does. It just does not necessarily appeal to the same exact customer as the S600. If the S600 is a business jet on wheels, it may be akin to a Boeing 737 Business Jet. A 14 liter V16 on the other hand can be looked at as Air Force One. An over the top car for over the top personalities. If not anything, it is a more differentiated product than an S600 wanna be packing a 6.0 DOHC V12 and a pair of turbos vying for the same customers who in the end will probably buy the S600 anyway because of brand and perception loyalty. As far as huge ass goes, 14 liter is not exactly "huge ass" it is merely the equivalent of two corvette motors. Huge ass will be something along the lines of the Daimler-Benz DB603 44.5 liter Supercharged Inverted V12 packing 4-valves per cylinder and Bosch Direct Gasoline Injection.

Actually, the segment has been relatively stable. It has never been a huge segment and it will never be, but it is a stable segment. Economic downturn or not, the clientele for V12s are not impacted as much as the middle and upper middle class. The middle and upper middle class do not buy V12s. The more over the top the flagship is, the better it will fulfill its mission of bringing prestige and recognition to the brand. Of course, grabbing a few big spenders along the way doesn't hurt. But, selling itself is secondary to helping sell the Bi-turbo V6 or V8 Omegas, not to mention CTS, XTS, SRX and ATS cars. If you want middle class business, lower the entry price of ATS or simply show them the way to the Buick dealership. In fact, a 14-liter V16 made using the equivalent of two pushrod LS7 V8s mated with a new block making about 1010hp / 940 lb-ft will be even better from a prestige standpoint. The problem of course is that there is no transmission for it and rear drive is no longer viable for putting all that power down.

A buyer of a $150,000 car isn't interested in ease of service and low maintenance costs. They want the best and they're willing to pay for it. True, but this car won't be $150,000. An S-class starts at $94,000, almost all the other competitors are $10,000+ less. I'd expect Cadillac to slot into the $75-95k range. Although buyers at that level still demand a lot. I have no problems with a Pushrod V8. It is in many ways a superior configuration than a DOHC V8. It is lighter, more compact, while having comparable or superior fuel economy to DOHC designs of equivalent power (even if these tend to be lower in displacement). I expect the incorporation of VVT, Direct Injection and cylinder deactivation to allow the Pushrod V8 to continue enjoying its superiority over DOHC designs in these regards. The issue here is the V12 -- because an Omega flagship deserves and can benefit from an over the top V12. A brand new architecture is both profoundly expensive and unnecessary when you already have a 90.6 bhp/liter 3.6 liter V6 in mass production from which to derive the engine. Sharing the pistons, rods, valves, springs, lifters, pumps, bolts and a myraid of components from a mature design made it high volume is a great advantage GM has over the competition. Trust me, nobody is going to ask the "question" does it use the same piston as a Malibu? And even less will care about the answer. I don't see a 7.2 liter displacement as demerit. There will be just as many buyers who will wear that 7.2 badge proudly as there will be those looking for a twin turbo twelve. The NA engine is simpler, lighter and less bulky. I know there are those who disagree here, but IMHO 640hp and 550 lb-ft is "enough". It also doesn't hurt that GM already has a 551 lb-ft 6-speed automatic in the parts bin. All that is needed is to modify the valve body and the shift logic so it readily accepts higher input shaft speeds. This is a lot easier than increasing the maximum torque rating which requires beefier gears and clutch packs.

Displacement is pretty far down on the list of things that increases fuel consumption. With the same cylinder count, same number of valves and other frictional elements, the difference in fuel consumption between a 7.2 and 6.0 V12 is negligible. It may not even add up to 1 mpg. If you need examples, just look at the 3.6 vs 3.0 V6 -- no difference in mpg numbers at all. Similarly, the 1.4T in the Cruze did not provide better fuel economy numbers than the Ford 2.0 in the Focus, the Hyundai 1.8 in the Elantra or Honda 1.8 in the Civic. Don't assume that reducing displacement always produce fuel economy gains. In fact, when you drop add turbocharging and the consequential reduction in compression ratio, you invariably also reduce thermal and combustion efficiency. A good example is going from 2.4 to 2.0 liters and piling on a turbo. In every contemporary case, from every manufacturer, we see a reduction in fuel economy. In anycase, fuel economy is not a top priority for a V12 flagship. The CAFE impact is irrelevant given the tiny volumes V12 vehicles generate. It's like asking how much Bentley's MPG numbers impact Volkswagen-Audi group... well it doesn't register at all. A 6.0 turbo will have torque problems -- much more so than a 7.2 NA -- and the 6L90 is rated at 551 lb-ft right where the torque output of a 7.2 NA will be. "Lightly turbocharged" engines make around 100~110 lb-ft per liter. That's about 600~ 660 lb-ft from a 6.0. Go any lower and you make turbocharging not worth effort. Increasing the input shaft speed is not nearly as difficult as increasing the maximum torque rating.

Doing a V12 from a V8 is a non-starter. The optimal bank angle is 60 degrees for a V12 -- same as the V6es. Whereas it is 90 degrees for a V8. The Mercedes V12 is a bi-turbo. It is not that powerful (603 hp) although it does make a 730+ lb-ft of twist. A naturally aspirated V12 of 600~640 hp and 550 lb-ft is plenty competitive. Being NA also means that it is a lighter and less complicated powerplant -- because you'll eliminate the turbocharger's exhaust ducting as well as a spaghetti of intecooler plumbing. As far as torque goes, 550 lb-ft is plenty and a higher peak is actually a good thing. There is no practical way to put 730+ lb-ft at 1800 rpm to the pavement at lower speeds; you'll just melt the tires. What you end up doing is electronically limiting the engine's output in the 1st 2 or 3 gears... As far as size goes, the a 3.6 is exactly the same size as a 3.0 externally, a 6.0 and 7.2 is similarly equal in dimensions. As far as being a 7.2, this is actually a good badge to have in the realm of over the top engines like a V12. Nobody is looking for marginally lower displacement here. If the customer is looking for frugality that or for practicality, he won't buy a V12 to begin with.

The Omega needs a V-12... let's hope they endeavor to create a stretched version of the 3.6 liter LFX block. Such an engine will displace 7.2 liters and produce about 640 hp @ 6800 rpm / 550 lb-ft @ 4800 rpm. It'll require a "high input speed" 6L90 transmission to fully harness (otherwise it'll have to be capped at 6200 rpm for an approximate loss of about 40 hp; which actually isn't too bad). A 3.0 or 3.6 liter Bi-turbo V6 -- making 360~430 hp -- will serve it well as an base power plant. If they want to do a hybrid, it can be clobbered together using the Bi-turbo V6 and the same Dual-Mode Hybrid transmission currently in the Escalade Hybrid.

I doubt it... an 8% weight reduction and similar aerodynamic drag (yes, its a little smaller in profile, but also a draggy hatchback) does not translate into an increase in fuel economy from 42 to 50 mpg. if I have to put a number on it, I'll say 1~2 mpg improvement in the city number, maybe 0~1 mpg on the freeway.

Its really a weight issue more than anything. The CTS is a porky car for its size. The same transmission (6L50) and engine (3.6 DI LFX V6) gets 30mpg in the Camaro. The Camaro of course is about 300 lbs lighter than the CTS.

It's a nice design. However, on the power train front I hope Cadillac will do something different rather than rehash the Volt. The ELR should be more than a Volt in a new body shell and with more amenities. It should be something special. If it's me, I'll make it a performance oriented Hybrid. ELR Performance Hybrid power train Type: Parallel Hybrid Internal Combustion Engine: 1.4L DI VVT Miller-Cycle Turbo inline-4 Engine Power: 130 bhp @ 4600~5000 rpm Engine Torque: 150 lb-ft @ 2500~4500 rpm Maximum ICE RPM: 5000 rpm Generator/Motor output: 55 kWe (74 bhp) @ 70 mph [Chevrolet Volt Generator/Motor] Battery: 4kWh Li-Ion [1/4 Volt's Capacity; no plug-in charging] Curb Weight: 3375 lbs 0-60 mph: 7.0 secs Fuel Economy: 50 (City) / 50 (Hwy) mpg

Well, if its me, the Corvette would end with the Z06. You can get the "regular" $45~50K Corvette or the Z06 for another $10~15 more. There would be no ZR1. Instead, the ZR-1 would be a Cadillac with a unique body shell and be called the 2nd Generation XLR-V. The 2nd Generation "regular" XLR can then have a 3.6 V6 Bi-turbo forcefed to the tune of 480 hp @ 4800~5800 rpm / 531 lb-ft @ 2200~4700 rpm. It's still a Corvette C6 platform, but with Caddy styling and superior cabin fittings. Things like magnetorological shocks, backup camera, Nav, Napa Leather Seats, active aerodynamics and Acoustic glass will be standard.

It's already years late. Even a turd car will get people back int the Cadillac showrooms. Not that this is a turd. Just bring it out already!!!! Yeah, with 20/20 hindsight this is a car Cadillac should have had 15-20 years ago when the compact premium market really started heating up. Better late than never, though. Actually, they did have a turd in this niche once long ago, but it's best forgotten. A turd? No. Two turds... Caterra, followed by BLS

Well, I am not saying that the Volt is a bad vehicle. What I am saying is that the Volt is a very expensive, very heavy, vehicle of mediocre performance. And, that it is that way because all the sacrifices and design choices made so it can be a short range pure electric plug-in. A vehicle that is lighter, faster, better handling and which focuses on maximizing fuel efficiency rather than being able to charge off a power grid, may be more interesting -- especially when it is $8000 to $10000 less with sportier looks and more luxurious appointments. No, neither the Volt nor the "Hypermiler Special" make economic sense from the perspective of saving gas. You cannot save enough gas to recoup the $12000~20000 premium over a well appointed, reasonably economical Cruze LTZ. Not at $3.50 a gallon, not even at $10 a gallon. A 2-seat coupe is not as practical as a boxy, slow, 5-passenger hauler. But the very premise of expensive hybrids is NOT practical to begin with. Despite people complaining about fuel prices, the priorities of the car buying public is certainly not fuel economy at any expense or compromise -- far from it. That is why Hybrids are a niche. That is why Hybrids account for 2% of vehicle sales despite tax credits and all the cajoling by the America's Political Class. Hybrids are about being cool and feeling good about being green. And, not everyone who is looking for that type of satisfaction is of the boxy car persuasion. And, most cannot afford a Tesla roadster or Model S. A 30K Coupe with mileage to brag about, Miata like handling/performance and mid-engine good looks IS a differentiated and currently unchallenged product worth considering.

With about 3.6 kWh of battery capacity and a 75hp motor. You have about 10 miles of electric range in a 2500 lbs vehicle even if you operate the battery at between 25 and 75 % charge for longevity. What this means is that typical stop and go sessions and short city hops where you don't floor the pedal is can be entirely electric. Or at least, 3~4 times more so than a Prius with half the capacity, less motor torque and 700 lbs more weight to lug around. The diesel is basically a cruise engine and a power adder when you floor the pedal. Neither 3-cylinders nor Diesels are that bad, especially small ones displacing 332 cc per cylinder which do not rev above 4000 rpm. The Turbo also gives the exhaust a turbine like whirl. The same concept can be implemented at 22~24K if you forgo the aluminum frame and body shell, and drop the Caddy level interior. That's take you to about 2800 lbs and the mid to high 60s in the MPG scale and about 8 secs to 60. Still not bad.