dwightlooi

None. Toyota is probably the closest... they have a controlling stake in Aisin, but it is not a wholly owned subsidiary. BMW/Audi uses ZF and independent maker's boxes.

A low volume hybrid uber sedan is even more cost prohibitive!

Which is where the 7.2 V12 becomes interesting. It is not a new engine done from the ground up. Its combustion chamber is exactly the same as that used in the 3.6. Its valves, valve springs, lifters, injectors, pistons, rods, pins, sprockets, ECU, you name it, are identical and interchangeable with those used in the utilitarian 3.6 V6. Even the cam grinds and the VVT programming comes largely from an everyday Chevy Impala's V6. What it really is is a new block/head casting and a new crankshaft, even these can be mostly the 3.6's model with the ends redone so they are joined into a longer engine. This saves a lot of engineering time. You don't have to spend months and months doing CFD to figure out the combustion and flow behaviors, you don't have to shape the intake and exhaust ports for proper flow. You don't have to figure out strength and durability needed for individual parts. And, when you are done, you share the overwhelming majority of parts with a high volume engine already in production. An engine like that can be done for less money than it takes to develop say the 7.0 LS7 engine in the corvette Z06 which afterall has unique internals which doesn't have much sales volume and is not used in any other car. In fact, I think the reverse is probably more likely to buying a V12 from someone. GM can probably sell this V12 to any number of fledgling boutique supercar makers looking for a V1 but can't afford to develop one or simply don't know how to do an engine right. It's effortlessly 600hp / 550 lb-ft right out of the box with a reduced 6200 rpm redline and a diet of 87 octane. That's no slouch. And, you can probably buy parts for it at your local discount autoparts store.

CAFE is a non-issue. GM sells about 2.3 million vehicles in the USA. They'll be lucky to sell 3000 V12s. That is in the order of 1/1000th. CAFE is calculated to 0.1 mpg, in other words the V12s could be 1 MPG and it still wouldn't register at 3000 vehicles.

The engine will probably launch on the C7 Corvette around 2013. Versions of it will probably replace the V8s in the Cadillac Vs, the Camaro SS, as well as GM's Light Trucks and full-size SUVs.

The LS3 is the engine currently in the Corvette and Camaro SS. It is a 16v Pushrod V8 without variable timing or direct injection. It displaces 6.2 liters and makes 436hp @ 5900 rpm / 428 lb-ft @ 4600 rpm in the Corvette (426hp @ 5900 rpm / 420 lb-ft in the Camaro). It is physically smaller and lighter (183 kg) than the BMW 4.0 V8 in the M3 (202 kg). Fuel economy is exemplary for its power class, delivering 16 / 26 MPG in the Corvette and 16 / 24 MPG in the rather heavy Camaro SS (3860 lbs). The LS3 is not the highest revving or most powerful of the current small blocks -- those honors will have to fall on the 7.0 liter LS7 (505hp) or and Supercharged LS9 (638hp). Rather, it represents the middle of the road, mainstream, version of the current generation of small block V8s. The LS family is considered the Gen IV Small Block V8. GM is currently working on its successor family -- collectively known as the Gen V Small Block V8. The Gen V engines are expected to retain the 2-valve per cylinder layout, but add direct gasoline injection, variable valve timing and cylinder deactivation as standard features. The Gen V engines, by virtue of direct injection and resultant increase in compression ratio alone is expected to make between 6~10% more power (~470 hp). Fuel economy is also expected to be slightly better, probably on the order of 1 mpg.

Well, we know what GM is currently doing. They are do a direct injected, variable timing equipped and cylinder deactivation capable version of the LS3. From a performance, packaging, weight or fuel economy standpoint such an engine gives no ground to a DOHC V8. A 60 deg DOHC V8 however will at least be similarly narrow as a pushrod 90 deg V8 and fit in the same approximate space. This engine will be economical to engineer and produce because it shares the majority of its component, design and assembly tooling as the high volume V6. It will also match the LS3's 420~432 hp with 23% less displacement, albeit with a torque deficit of 60~70 lb-ft. This does not necessarily translate into better fuel economy because of the higher parasitic frictional losses of a DOHC design and it does incur an MPG penalty. On the flipside, because the pistons are smaller and strokes are shorter the vibrational forces are also milder while rpm limits are higher. The reduced rotational inertial also makes for a faster revving engine. Is this a better engine for Cadillac in lieu of a advanced pushrod? That is debatable. It will however be more like what the Europeans, Japanese and Koreans are offering both in terms of displacement as well as specific output. Again, whether it is better to be like everybody else, is debatable. It will also have a tax advantage in Global Warming coolaid drinking countries with a displacement tax, however this is probably not a significant consideration for a V8, unlike more economy oriented V6 and I4 offerings.

The very premise of an LFX derived V8 is that it uses the same exact valves, springs, lifters, bolts, rods, pistons, sprockets, chains, accessory drive, combustion chamber geometry, intake design and the whole nine yards. The difference being a new block casting for two more cylinders, a new crankshaft and accommodations somewhere for a balance shaft. Retaining the the 94 x 85.6 mm (bore x stroke) of the 3.6 V6 and adding two cylinders yield ((94/2)^2)*3.1416*85.6*8 = 4752 cc

Well, the 3.0 was a mistake... It was mismatched to the heavy SRX and was painfully slow while offering NO fuel economy advantage whatsoever over the 3.6. The 3.0 was 18/25 for the FWD. The 3.6 is also 18/25 for the FWD version. The car should have gotten the 3.6 to begin with. Good thing it is for 2012. To be fair, it wasn't really a guzzler. The RX350 posts identical MPG numbers (18/25), it is just not as slow because it is lighter. That GM was able to hold the MPG numbers despite a 400 lbs weight deficit is actually... quite remarkable.

Well, the reality is that GM IS working on an 8-speed and it'll be ready in about 2 years time. Multiple versions will be needed to cover 170 to 600 lb-ft, and they are not all going to happen at once. The logical thing to do will be to fill the mid-range models with 8-speeds first, while the entry level models and big V8s wait. BMW did that too... the 3-series stuck with 6-speeds while the 5 and 7 got 8-gears. This keeps the 3-series price low (for now). M-B kept its V12s and AMG V8s on 5-speeds while the E & S class moved to 7-speeds because the initial 7G-tronics did not handle the torque of the megamotors. Also, the Megamotors actually did 0-60 faster when they went to taller final drives because it saved one shift before the 60 mph mark.

There is no V8 version in existence or under development. However, if there is, it will displace 4752 cc (4.8 liter), sport a compact 60 degree Vee angle and probably require a balance shaft to be refined. It'll also probably make about 420~430 hp and 365~375 lb-ft on regular 87, perhaps 20 more on 91 octane. Its use however will require that GM revamp its transmission lineup, because an LFX derivative V8 will make its maximum power at about 6800~7000 rpm. Currently, all GM automatic transmissions capable of handling over 300 lb-ft of torque have either 6500 rpm or 6200 rpm maximum shift speeds.

I want to keep this a simple poll so forgive me if it seems to lack the typical depth I tend to dwell into on various subjects. The basic premise is this... A 3 cylinder engine is more economical on fuel than a 4-cylinder A 3 cylinder engine is also more compact, lighter and cheaper to build A 3 cylinder engine is more miserly on fuel because it has 25% fewer frictional elements (valves/cylinders/bearings/rods/etc) A 3 cylinder is also easier and more efficient to turbocharge* A 3 cylinder is, however, slightly less refined than a 4 cylinder even with a Balance Shaft added * The reason a 3-cylinder is easier and more efficient to turbocharge is because a 3-cylinder engine does not have the exhaust valves of two cylinders open at the same time. In a 4-cylinder engine two pistons are always at top dead center, when other two is at the bottom dead center. This means that whenever one cylinder opens its exhaust valves open at the beginning of its exhaust stroke, another cylinder is at the end of its exhaust stroke / beginning of intake stroke. This means that unless a dual scroll turbo and segregated exhaust mannifold is used, the high pressure exhaust gas from the cylinder beginning is exhaust stroke can back flow into the cylinder beginning its intake stroke. This leads to poor aspiration, emissions issues and reduced turbocharger response (due to lost exhaust energy). A dual scroll system is not only more expensive to fabricate, it also introduces additional flow restrictions into the exhaust path. Hence, with a dual scroll system you are trading a little top end flow capacity for improved response. A 3 cylinder engine does not have pistons at the top and bottom of their travel at the same time and hence does not have this problem. A 3 cylinder engine can therefore use a single scroll turbo with equal or higher efficiency a 4 cylinder using a dual scroll turbine. The question is, if it comes down to you and your money, which engine will you prefer in the next refresh of the Cruze and/or the Sonic? 1.4 liter 4-cylinder Iron Block, Aluminum Heads, 72.5 mm x 82.6 mm (Bore x Stroke) Direct Gasoline Injection, DOHC-16v, Intake & Exhaust Variable Valve Timing Honeywell-Garrett MGT15D turbocharger, air-to-air intercooling 170 hp @ 5300 rpm 170 lb-ft @ 2000~5200 rpm 6500 rpm rev limit 87 Octane Unleaded 1.5 liter 3-cylinder Aluminum Block & Heads, 86 mm x 86 mm (Bore x Stroke) Direct Gasoline Injection, DOHC-12v, Intake & Exhaust Variable Valve Timing Honeywell-Garrett MGT15 turbocharger, air-to-air intercooling 170 hp @ 5300 rpm 170 lb-ft @ 1900~5200 rpm 5500 rpm rev limit 87 Octane Unleaded

The SRX isn't quite the RX350. At least not in terms of sales, at least not yet. But it is making a lot of inroads. The biggest problem with the SRX isn't that its FWD. Its that it is about 300~400 lbs heavier than it ought to be. This lead to acceleration that is sufficiently lethargic that even the soccer moms felt it. Ditching the 3.0 for the 3.6 helped. This car really needs the LF3 (3.0 Bi-turbo) more than any other right now.

(1) I think a V12 is supposed to be over the top... no environmental or fuel economy concerns when it comes to a V12. Customers who care about such things won't buy one anyway. One of secondary reasons you may want a smaller engines -- lower vibrations -- is also irrelevant in a V12 since it is completely naturally balanced. (2) GM will phase in 8-speed transmissions. The first engines to get paired with an 8-speed will be those who need it most and the first cars will be those which aren't overly price sensitive. I see the 8-speeds going into the V6s first. The mega-torque (supercharged) small blocks and up will probably soldier on with the stout 6L90 for a while, if not anything because they can afford to simply go to a taller final drive for fuel economy. The entry level cars like the 4-pot ATS will also probably continue too use the 6-speed 6L45/6L50 simply because it is cheaper to shave about $1K off the entry price to the class. (3) I believe Caddys will eventually get Opel Diesels. If not for the US market, for the EU. (4) As for CAFE, I have always believed that GM should build cars that customers want to buy. CAFE should be allowed to fall where is may. The reason being that there is no law saying you have to comply with CAFE or cease operations. If you don't comply -- either because you can't or you flat out won't co-operate with the visions of Washington DC -- the fine is actually tiny on a per mpg and/or per vehicle basis. It is better for instance to pay a $5.50 x 50 = $275 fine for missing CAFE by 5 full MPGs than to force $3000 worth of fuel saving hardware or underpowered engines onto consumers do not necessarily want to pay for them or live with them.

Cadillac can do a car like the Sixteen. But it will be a Halo car and not a volume or profit driver. As such, the priority should be to get the ATS out followed by an STS/SLS replacement. The Sixteen can be Cadillac's Maybach, but it cannot be Cadillac's S-class. Like the Maybach, the Sixteen would be nice, but it is not necessary for the brand's success. If they do build it, they may as well go overboard. A new block casting siamesing two LS7s will produce a 14-liter V16 engine with 1010 hp / 940 lb-ft engine -- 9 horses more than the original Bugatti Veyron. That's for all intents and purposes... enough.

I think you'll find the 5th Gen small blocks to be more than decent. Delivering 450~470 hp and ~25 hwy mpg in a 4000 lbs car -- all while being physically smaller and lighter less than a BMW 4.4 -- with the aid of direct injection, variable timing and cylinder de-activation, this is not going to be your grandfather's small block. In many ways, a 6.2 badge is not a negative. And, for people and countries who shun that, a 3.0T would have been their cup of tea. I wasn't too fond of the "Ultra" DOHC V8 -- Northstar's still-born replacement. I felt that it was the wrong formula. It didn't offer what the competition didn't. If GM wanted a DOHC V8 I think they should do it as a 60 degree engine based on the High Feature V6 family. This would have at least been a very narrow and compact V8, that is also economical to develope and produce. Also, the HF V6 is capable of reaching 90hp/l on 87 octane and the 4.8 liter displacement would have been roughly were they would have wanted it to be anyway. A 60 deg engine based on the LFX would have been about 420~430hp / 365~370lb-ft. A single contra-rotating balancer would have made it on-par with the Volvo 4.4 V8s which is amply decent.

Well, I didn't think the ETS (XTS) should be a caddy either. But I think this car is already 100% confirmed. The 3.0 Bi-turbo (LF3) is also something that has been worked on for a while. I do not know why they chose the 3.0 liter displacement. Maybe its because the BMW I6 turbo is a 3.0, maybe its because the 3.0 block has thicker cylinder walls. The 7.2 V12 is simply two 3.6 V6 blocks mated together in a new casting. It'll be about 600hp whereas a 6.0 will be about 540hp. The 3.0 poses two issues. The first being that it is less powerful than the Supercharged small block V8 which makes it a hard sell as the flagship motor. The second being that even to get to 540 hp (90hp/l) the 6.0 would have to rev to 7000 rpm. Currently, GM's 550 lb-ft transmission -- the 6L90 is capped at a 6200rpm maximum shift speed. The volume of these mega torque engines will be small and it makes it hard to justify a new transmission -- especially if it has to be done by 2014. Also, a 7.2 is unique, being bigger and more powerful than its teutonic competitors. As far as the displacement tax in some countries and the perceived "greeness", both a 6.0 and a 7.2 V12 would have blown that out of the water.

Well, its a V. It's supposed to be dramatically more powerful than the the regular 3.0T. The question is whether the 360hp 3.0T compares well with the 535, 550, E350 and E550. I think it does, slotting in between the 300hp 535 and the 400hp 550 (4.4 Bi-turbo V8). 360hp is ample motivating force for the majority of mainstream drivers who want a little kick but not necessarily a supercar. If a performance oriented driver comes along there is always the CTS-V with 600 horses and at a lower or similar price point to a 550i. On diesels, the intent is to have a 2.0T @ 190 hp and a 3.0T at 270hp -- for the Europeans only. These are Opel derivative engines. (See the last bullet point in the foreword text)

Greater refinement + 48 more horsepower.

The following is a plausible Cadillac vehicle-powertrain lineup for the 2015 model year. Each model (with the exception of the ETS) gets two mainstream engine choices + a "V" edition ATS joins the lineup targeting the BMW 3-series / Mercedes-Benz C-class with the new Alpha Platform ETS joins the lineup targeting Lexus ES buyers with the Epsilon 2 Platform STS / SLS (long wheelbase) returns as the flagship on a the Zeta 2.5 Platform XLR returns on the Corvette C7 platform supplying supercar credentials The 2.0T provides the ATS with an efficient and linear entry level engine The 3.0 Bi-turbo DOHC DI V6 joins the mainstream engine lineup The 6.2 Pushrod Small Block V8s return fortified with Direct Injection and Cam-in-cam Independent VVT Hybrids Options (Not shown on chart) are available as options mated with 2.0T, 3.6 and 6.2 NA engines Diesels Options (Not shown on chart) are available in Europe using Opel 2.0 (190hp) and 3.0 (270hp) CDTi engines Comments Welcomed!

IMHO, this should have been the "standard" Turbo Regal. The 220hp version should never have existed. What would have been better would be a 182hp NA four for those who don't care about making brisk pace, and a 270hp turbo four as a V6 replacement for the model. 270hp is what the 3.0 V6 makes. 270 hp is also what the Sonata Turbo makes. 270hp is not some astronomical number worthy of being reserved for a "GS" model. Doing this probably does not change the cost equation at all since the 220 and 270hp versions of the engine have essentially identical complexity and technological content. If they wanted a "GS", it should have been introduced as a 300~360hp 3.0 LF3 Bi-turbo with AWD and an advanced center and/or rear differential.

It has been suggested that there should perhaps be a decontented, perhaps V6 powered Corvette to try to lower the price and make the car more accessible folks in their 20s and 30s. This begs a very simple question -- why not make a car that appeals to this demographic that isn't necessarily a Corvette? Let's call it the Chevrolet Speed Mid-engine Rear-Drive, 2-seat Coupe w/Scissor Doors, 2950 lbs Hi-Per Struts (Front), Chapmann Struts (Rear), Magnetoreological shocks (Optional) 245/40 R18 Tires (Front), 275/35 R18 Tires (Rear), 4-piston Calipers (All Around) Transverse 2.0 DI-Turbo 4-cylinder Engine (300 bhp @ 6000 rpm / 270 lb-ft @ 2800~5800 rpm / 6350 rpm Rev Limit) 6-speed Manual or 6-Speed Automatic Transmission 0-60 in 5.0 secs $29,995 It doesn't have to be a Corvette

EPA Fuel Economy (2011 model year)... Chevrolet Camaro SS -- LS3 6.2 Pushrod V8 -- 3860 lbs -- 16 / 24 mpg BMW M3 Coupe -- S65 4.0 DOHC V8 -- 3704 lbs -- 14 / 20 mpg Mercedes C63 AMG -- M156 6.3 DOHC V8 -- 3924 lbs -- 12 / 19 mpg Nissan GT-R -- VR38DETT 3.8 DOHC V8 -- 3800 lbs -- 15 / 21 mpg

There are many (usually very expensive) cars that are more powerful and lighter than the Corvette. But they are not lighter and more powerful because of their DOHC engines; they are actually heavier than they would otherwise be if they had used a Pushrod V8. At the same output, a DOHC motor tends to weigh more and take up more space under the hood. However, the use of exotic materials and construction techniques can often allow the entire car to be lighter and more agile. The same materials when used with a compact and powerful pushrod powerplant will return even better performance. Let me give you some specific examples... LS3 6.2 Liter Pushrod V8 (Corvette / Camaro SS) -- 436 hp / 428 lb-ft -- 183 kg LS7 7.0 Liter Pushrod V8 (Corvette Z06) -- 505 hp / 470 lb-ft -- 206 kg S65 4.0 Liter DOHC V8 (BMW M3) -- 420 hp / 295 lb-ft -- 202 kg VR38DETT 3.8 Liter DOHC Twin-Turbo V6 (Nissan Skyline GT-R) -- 485 hp / 434 lb-ft -- 276 kg As you can see, the pushrod engines are lighter than comparably powerful DOHC V8 and DOHC Bi-turbo V6 solutions. Because of the lack of fat, bulky, DOHC heads and/or turbocharging/intercooling hardware, a naturally aspirated pushrod V8 is also more compact. If you compare the fuel economy numbers of similarly heavier cars using these engines, you will also notice that the Pushrod engines give up no fuel economy to their DOHC and Turbo V6 counterparts. In fact, they are frequently more miserly on fuel -- just compare the Camaro SS's MPG numbers with that of an M3 or C63 AMG, you'll see where they fall. As far as refinement goes, a GM 6.2 liter pushrod V8 is no less refined than a Mercedes 6.3 liter DOHC V8. It is only less refined than a BMW 4.4 liter V8 for instance. This has nothing to do with the valve train layout. It is simply that a larger displacement engine tends to be less refined than a smaller displacement one of the same cylinder count, owing to the heavier reciprocating mass inside it. And, really, the current breed of GM 6.2s are not bad at all.

That is actually highly debatable. The C63 and C55 had no problems being accepted by the "rest of the world". Fact of the matter is that despite displacement taxes, and all the CO2 capping silliness based around the scientifically bankrupt notion of Global Warming, buyers of cars in the category of the C63, M3 and potentially ATS-V or Corvette are not particularly concerned about the extra dollars or Euros the politicians impose of their cars. Also, if you enter the fight with a 4.0 DOHC V8 instead of a 6.2 Pushrod V8 you are tendering a product that is less differentiated and more like everybody else's, while giving up performance and taking on weight. What GM needs is a good I4 and V6 for the mainstream models targeting mainstream buyers. Cars like the Vette and the Caddy-Vs can be big displacement and be proud of it. Why not offer both a Bi-turbo V6 or V8, alongside a Pushrod big displacement V8? Because such an engine does not currently exist and creating one done to the 420~470hp trim required for a Corvette is developmentally expensive. This problem is compounded by the fact that the Corvette and Caddy-Vs are never going to be high volume cars. It also increases unit costs and degrades performance. This creates a marketing dilemma... how do you market a slower, heavier and more expensive car alongside the small block powered version? What exactly is the sales pitch? It's slower, heavier and more expensive, but you should buy it because it is DOHC and has a turbo whistle? GM should not choose to continue with the pushrod V8 because it is cheaper or because they don't want to learn how to build a good DOHC engine. It should do so because it is superior. And it is, in power output, fuel economy, size and weight. The only draw back really is the increased vibrational harshness -- not so much from the valvetrain but from the larger piston slugs going up and down. But in a car like the Vettes and the Caddy-Vs this is acceptable -- in the same vein that the drastically increased vibrational harshness of a flat-plane crankshaft is deemed acceptable in Ferrari's.