dwightlooi

C63 is 451 hp, but in the black series it is 510 hp E63 is 518, but 550 hp with the performance package. S63 with performance package is 564 hp and 664 lb-ft. Well, from 2007 up till 2010 M-B used the same 6.2 liter M156 in the C63, E63 and S63 AMG, albiet with different tuning for the C, E and S-class AMG cars. In 2011 the S63 switches over to a 5.5 Bi-turbo V8 and in 2012 the E63 did the same. But the C63 is still on the 6.2 NA V8 and it will remain so until the next generation at least. Previously, up till 2006 M-B used a NA 5.4 liter M113 V8 in the C55 and a Supercharged 5.4 M113 V8 in the E55 and S55 AMG. They never had an issue with not wanting an E-class or S-class because of any of these. A 450~470hp class NA V8 in the ATS and a 550~600 hp class SC V8 in the CTS-V offers more than ample power train differentiation. But even if there is no engine differentiation, it won't really affect the desirability of the CTS-V -- people who buy it will buy it simply because it is a bigger and better equipped car. The problem with a TT V6 is that:- An appropriate (450hp class) TT V6 does not yet exist so it'll have to be developed -- unlike the C7 V8 engine which will be ready to be plucked one ATS-V or no ATS-V If it is developed there will be poor economies of scale because there will be no other application (a 360hp V6TT will be used for other vehicles It will have some degree of turbo lag however mild that turns out to be. It will be more expensive than a Gen V Pushrod V8 It will weight more than a Gen V Pushrod V8 It will have a more demanding maintenance schedule than a Gen V Pushrod V8 It will be less desirable to some buyers It won't have a power advantage to justify the above It won't have a big enough fuel economy advantage (if any at all) to justify all of the above All it'll have is the ability to say DOHC Twin-Turbo and that isn't particularly unique on the market place.

I doubt it... The 3.6 engines have a bore center spacing of 103 mm and a bore diameter of 94mm. This means that the cylinder walls are 9 mm thick. Getting to 4.0 liters by enlarging the bore will require enlarging the bore to 99 mm. This leaves 4mm of metal between the cylinders which is ridiculously thin. To put the numbers into context, the 2.5 liter four has has 8mm of wall thickness, the 2.0T has 10mm, the 3.0 V6 has 14 mm and the 6.2 V8 has 8.5 mm. Enlarging the bore also entails a lot more additional changes than simply using thinner tron sleeves. Putting bigger slugs in there doesn't do any good unless you also put bigger valves in there. Putting bigger valves means a head with bigger intake and exhaust passages. These in turn require a new intake manifold and exhaust collector. If GM is looking for more than 323 hp, the answer is already in the works. It's called the LF3. A Bi-turbo version of the 3.0 V6. This can make between 300 and 400 hp using reasonably levels of boost, with about 360 being what I'll expect for applications like the Silverado, Acadia or XTS. Well ok, couldn't some of the increase in displacement come from stroke? I am certain that the max displacement on the block is 4.0 somehow. Sure, but you said "by swapping out the cylinder sleeves" ...

Not cold fusion, just a 130 year old engine operating cycle. If you are wondering where the 20/32 mpg comes from, well it's an educated guess based on the following:- The Corvette (3250 lbs) already gets 16/26 mpg today with the 6.2 liter port injected LS3 engine. Direct Injection, Higher Compression and other improvements on the Gen V V8 should produce a 1 mpg improvement An expected 200 lbs reduction in vehicle weight, better aerodynamics and taller gearing is good for another 1 mpg increase We are already at a decent 18 / 28 mpg for a 6.2 liter Gen V V8 with the above changes Now, cylinder deactivation cuts the operating displacement in half, Atkinson cycle further reduces that by 30% and improve energy recovery from each fuel-air charge. The net result should be similar to using a (6.8 / 2 * 0.7) = 2.4 liter 4 cylinder engine on a Corvette, for which a 10~15% reduction in fuel consumption is a reasonable guess. 20/32 mpg is 11% and 14% better than 18/28 MPG respectively. No Cold Fusion required.

It is one thing to offer a tuner kit to enthusiasts and quite another to adopt such a tune across the board. Enthusiasts probably won't mind a split IC cap in 5% of the vehicles, and they will probably tolerate or even love an engine that does not reach full boost until 3000 rpm instead of 2000 rpm and is peakier in the sense that max power arrives sooner at 4800 rpm rather than 5500 rpm, or an engine that feels stronger at 5000 rpm than at 6300 (not as linear as stock). The general public wants the engine to feel like a very linear V6 like the 3.6 and cry bloody murder to consumer reports when a hose clamp leaks even though it is a $5 fix. I never claim that GM cannot tune the 2.0T to 300hp or even 340hp. I am saying that they probably don't want to considering that 270 already at the top of the class, is extremely linear with 234 lb-ft available from 1500 rpm to 5500 rpm (260 lb-ft @ peak) and is as reliable as they want it to be.

http://gmpowertrain....inProducts.aspx Wall thickness = Bore Spacing - Bore Diameter The bore spacing is the distance between the center of each of the cylinders. Because half of each piston occupies the the space between the bore centers, the maximum available space left for the cylinder wall between each pair of cylinders is Bore_Spacing - ((Bore_A / 2) + (Bore_B / 2)). Unless your engine have different bore sizes from cylinder to cylinder, this simplifies to Bore_Spacing - Bore_Diameter. This assumes siamesed cylinder walls which is what most of these modern engines have. In some cases wall thickness can actually be less because they cut a water gap between each cylinder to improve cooling between them. However, it is impossible for the wall thickness to exceed that derived from the above formula.

Let me refine this concept further... 6.8 liters, 439 hp, 20 / 32 mpg In contrary to popular rumors that the Gen V Small Block V8 will be downsized in displacement, I believe that there is a possibility that it will actually be upsized. I am not saying this because I believe that GM is flagrantly going to disregard any fuel economy concerns or because the designed power output for the next corvette engine need to exceed 500 hp (naturally aspirated). I am saying this because the most economical 450 hp may not be a 5.5 liter V8 but a 6.8 liter V8. Sounds ridiculous? Well, read on and you will see that it actually isn’t. There are two concepts I want to discuss here. The first is Mass Efficiency. You’ll notice that a 4.8 liter Small Block V8 is not significantly (if any all) lighter than a 6.2 liter. This is because when you change the bore diameter and stroke length without altering the bore spacing the block and heads are roughly the same size and the cylinder walls are actually thicker. This applies to all engine families, in all configurations, from all makes, not just to Smallblock V8s. Hence, the most mass efficient engine tends to be the one that stretches displacement as much as possible given bore spacing and external dimensions. In short you want the engine to be as big on the inside as possible for a given exterior size. This leads to the best power to weight ratios and power to size ratios. Traditionally this has been a strong suit of pushrod designs and a weak point of DOHC designs. Why 6.8 liters you may ask? Because this is the displacement you arrive at with the LS3’s bore dimensions which is thick enough to accommodate supercharged applications and the LS7’s stroke which is the longest GM could squeeze into an LS block. 103.25 x 101.6 gets you 6.8 liters out of eight pots. The second concept here being that adopting "Atkinson Cycle" is more effective at reducing brake specific fuel consumption than reducing engine displacement. Some of you may be familiar with the term “Atkinson Cycle”. The Prius, Fusion Hybrid, Volt and many other efficiency focused cars use “Atkinson Cycle” engines. To put it simply, an “Atkinson Cycle” engine is simply one which closes its intake valves very late causing part of the intake charge to be pushed back out the cylinders during the piston’s upward stroke. “Atkinson Cycle” engines achieve two things by using this mode of operation. Firstly, they reduce the effective displacement. If you kick 30% of the intake charge out you are effectively aspirating and burning fuel like an engine with 70% the displacement – you make less power and burn less fuel. Secondly, and perhaps more importantly, it makes the compression stroke 30% shorter than the power stroke; or the power stroke 43% longer than the compression stroke depending on how you look at it. This allows a greater expansion ratio and hence better energy extraction from each drop of fuel burned. Its like having a longer barrel in a rifle, the same power charge and the same bullet gets to a higher velocity and higher kinetic energy because there is more bore room and time for the expanding gases to accelerate the projectile. The Prius for instance uses a 1.8 liter Atkinson Cycle Engine making a paltry 98 hp. That same 1.8 liter engine in regular Otto Cycle trim makes 140hp and Totota’s 1.3 liter engine makes 99hp. Why will the Prius – a contender for the fuel economy crown – use a 1.8 liter Atkinson instead of a 1.3 liter regular engine? Because a 1.8 Atkinson is more economical than the 1.3. It’s that simple! A 6.8 liter Gen V V8 would normally make about 517hp (assuming a modest 5hp/liter specific output improvement over the LS engines due to Direct Injection). If we run an Atkinson Cycle cam on it that keeps the intake valves open ~30% into the compression stroke we end up with a 362 hp V8. But this 362hp 6.8L V8 will be more economical on fuel than a 4.8 liter V8 with the same output in the same manner that the 1.8 Toyota 2ZR-FXE (Atkinson) is more economical than the 1.3 Toyota 1NR-FE engine of the same approximate output. That’s not the end of the story, because with Cylinder Deactivation things get even more interesting… you see the Gen V engine will only need to strive for maximum efficiency during low load and cruise operations. That’s how you improve EPA MPG stats and turn in real world economy when people don’t drive with a lead foot. When somebody is burning tires, trying for a 1/4 mile record or simply trying to pass a semi on a 2-lane highway, trust me, they are not interested in fuel economy during that burst of acceleration. Hence, only the 4 cylinders that does not get deactivated by AFM needs an Atkinson intake cam lobe, the other four can have a full performance Otto Cycle cam. The resulting engine designed with 4 Aktinson cylinders and 4 Otto Cylinders will have about 439hp and all the fuel economy benefits of the 362 hp full Atkinson engine featuring cylinder deactivation – at least will when accelerating judiciously and while cruising. How does a 439 hp 6.8 liter Direct Injected Gen V V8 with 20 / 32 mpg sound? Pretty Interesting to say the leastand roughly where the C7 Corvette needs it to be. All of the above is also consistent with the official GM claim that the new Gen V V8 will feature a “Brand new combustion system” – this is brand new indeed.

I doubt it... The 3.6 engines have a bore center spacing of 103 mm and a bore diameter of 94mm. This means that the cylinder walls are 9 mm thick. Getting to 4.0 liters by enlarging the bore will require enlarging the bore to 99 mm. This leaves 4mm of metal between the cylinders which is ridiculously thin. To put the numbers into context, the 2.5 liter four has has 8mm of wall thickness, the 2.0T has 10mm, the 3.0 V6 has 14 mm and the 6.2 V8 has 8.5 mm. Enlarging the bore also entails a lot more additional changes than simply using thinner tron sleeves. Putting bigger slugs in there doesn't do any good unless you also put bigger valves in there. Putting bigger valves means a head with bigger intake and exhaust passages. These in turn require a new intake manifold and exhaust collector. If GM is looking for more than 323 hp, the answer is already in the works. It's called the LF3. A Bi-turbo version of the 3.0 V6. This can make between 300 and 400 hp using reasonably levels of boost, with about 360 being what I'll expect for applications like the Silverado, Acadia or XTS.

Yes, it would be possible without too much cost to have a "High Output" 3.6 specially for Cadillac, or perhaps Cadillac & Buick. It'll need more than an ECU program change and exhaust work though. The 3.6 is pretty optimized as it is. To get notable gains out of it will require, among other things, raising the compression of the LFX engine from 11.5 to 12.5:1, swapping out the cams, widening/shortening the intake tracts, revamping the 6-speed auto transmission (or making the HO engine a Manual Trans exclusive item) and mandating Premium Fuel. Such an engine will be around 100hp/liter (360hp) vs 89hp/liter (323hp) the LFX is currently churning out. The 91 octane Fuel requirement isn't particularly objectionable for a luxury given that it is the norm with the competition anyway. The others however are kinda turn offs for GM. Raising compression means unique pistons, new cams means a different set of cams, new intake tracts means unique head variant and plenums -- all of which take away from the economies of scale. These however pale in comparison with needing a new transmission. A new transmission is needed because the 6L50 6-speed auto has a maximum shift speed of 7000 rpm. A higher output 3.6 with better breathing will peak higher -- probably between 7500 and 8000 rpm. If the transmission must shift at 7000, that defeats all the tuning put into the engine. GM currently does not have an automatic that goes that higher and a new transmission variant is a big ticket item -- perhaps more so than new engine. In the end, GM figured that 321hp is enough. And, using the (mechanically) the same engine represents a bigger benefit than getting an extra 30~40hp. Being on 87 octane though not much of a selling point to the luxury crowd certainly didn't hurt either. As far as the 2.0T I think they believe that 270hp/260 lb-ft represents the best balance between lag, longevity, power delivery and specific output. Going higher means more boost. More boost always equal more lag because more time is needed by the turbos achieve a higher boost pressure. It also means more rpms for the turbines which shortens longevity -- although the precise extent of which probably won't be apparent until past 150,000 miles on the odo. It also means a less linear power delivery because the boost will peak later and the horsepower will peak sooner. (Eg. you'll go from 270hp @ 5500 / 260 lb-ft @ 2200 to 300hp @ 4800 / 330 lb-ft @ 3000) -- whether is this objectionable is subjective but the physical effect is a given. Finally 270hp is already best in class and for all intents and the right distance from the 321 from the V6. I believe that GM will detune the Chevy and Buick versions of the engine rather than push the Caddy version further. What will happen is that the Buick and Chevy renditions of the 2.0T will be detuned to the possibly around 250hp. But that is just an educated guess.

Nah... the Northstar has too much negative baggage associated with it -- a spotty reliability record with earlier renditions and a mediocre performance throughout its life. I am not sure anyone ever revered Northstar or was impressed by its performance. Although it was a decent enough engine it was never truly impressive in any way. If they want to name their V8s and stick to the same theme, try Polaris. It means North Star and it is the US's first submarine launched nuclear ballistic missile. Polaris is also a snowmobile/snow machine. Not sure they would want to use that one. Just as the Camaro and ATS having the same identical engines be all good with you. Most people who are buyers in this call like to feel they are getting something special and more even if they are just fooling themselves. While the Camaro engine is fine it does not fool most of them. Engines are more than just a bunch of assumed numbers in this class people want to look and feel special with the car and what it offers. You want to prevent the detractors from pointing out it's just a Chevy with more chome. Here is a good example of marketing that GM did get right. The Alpha was designed and built for Cadillac first. It will next be shared with Chevy. On the other hand it would have hurt them to build it as a Chevy and then share it as a Cadillac. While it is still the same damn thing people precieve this as Chevy being based on a better platform vs the Cadillac just being a fancy Chevy. People are idiots and if you play the platform or engine shell game you have to keep the ball moving. It is not a sin to pass things down from Cadillac but it is a sin to pass Chevy things up to Cadillac. It makes a difference in how it is precieved by the general buyers. In this day and age it is easier to built a car vs market as marketing today has become even more important since there are so many models so close together. (1) The same argument about engines can be made regarding sharing of power plants between Nissans and Infinitis, Honda and Acura, Toyotas and Lexus, or VW and Audi. In fact within the GM family one can say that no one will want a ATS 2.0T because the Malibu will have a version of that engine, or a 3.6 DI V6 CTS because and Impala also uses that engine. If you go with a 3.0 LF3 Bi-turbo V6, I can guarantee that it will also be shared with a chevy, a buick or GMC -- that is going to be a 360hp class V6 applied across a large number of GM vehicles who needed more omph than the 3.6, sorta GM's answer to the Ford Ecoboost 3.5. It is not going to be an ATS only powerplant. Fact is, this hasn't been a problem with any of the aforementioned automakers, GM included. And, it will be completely impractical for Cadillac to have its unique engine lineup not shared with anybody because it'll add $10000 to the price of the car from high production costs and R&D amortization due to pitifully small volumes. (2) As for as which brand a platform is launch first with, that matters even less. People who are well informed know that a Cadillac and a Chevy built on the same platform are vastly different cars in the same manner that a Honda Civic is not an Acura ILX. People who don't probably don't know what "platform" is much less which model used what!

The problem with staying with the Inline-6 was that you have only six cylinders. And, they have already wound the 3.2 I6 to 8300 rpm and 333hp. Getting more power out of a six would require making the displacement bigger, rev it even higher or using forced induction. Making the displacement bigger is problematic because larger combustion chambers are more prone to knocking due to increased spark distance to the walls and because increased piston mass and stroke lengths limits maximum rpms. Reving the 3.2 I6 even higher than 8300 rpm is problematic because they are already at the limits of what can be made durable and reliable at sane prices. Using forced induction was frowned upon because the M3 was known the its razor sharp throttle response with its individual butterflies and going to turbos will result in some lag between throttle input and maximum boost hitting -- this can be minimized but it can never be eliminated. They really needed more than 333hp to be competitive and all the I6 options weren't ideal. So they went to a 4.0 V8 -- small cylinders, similar revability, 412hp, zero lag. That was then... now they are going back to the six because it can get them better mpg numbers than the DOHC V8 can and BMW feels that that is more a priority now than it was 6~7 years ago. The 3.0 Turbo I6 gets 20/30 mpg on a high compression, low boost regime. With a high boost, low compression regime needed for 400+ hp it won't do quite as well, but 17~18 city / 25~27 highway pretty good. Certainyl better than the 14/20 out of the 4.0 DOHC V8. The key here is that the 4.0 DOHC V8 really sucks compared to the GM Pushrod V8s in fuel economy despite displacing less than 2/3s the Small Block's displacement. Port injected in both cases, the GM 6.2 LS3 beats the BMW engine 16/24 to 14/20 out of a Camaro that weighs 100 lbs more than the M3. With the addition of direct injection and cylinder deactivation we can only expect slightly better figures with the Gen V version of the Smallblock. This brings us to the same 17~18/25~27 ballpark. GM has a great and efficient V8 architecture mature and ready to go, BMW doesn't. That's the difference.

(1) Because you don't want to pay Cadillac price for a car that will be out performed by one powered by the V8 that is architecturally similar to that used in a Silverado. Why would you want to pay Cadillac price for an ATS-V when a Camaro SS is faster, more responsive, better balanced and just as good on mileage? (2) Because the sports car small block V8 is not the same as the Silverado. The tuning is completely different; whereas the Vortec V8s in the trucks and the LS V8s in the Corvette and CTS both use pushrods and 2-valves per cylinder, the former is tuned for low octane fuel and towing torque, while the latter is tuned for responsiveness and higher rpm horsepower. Saying that they are the same is akinned to saying the the Toyota Tundra DOHC V8 is the same as the IS-F or LS460 DOHC V8 just because they share the same valvetrain configuration. Why would anyone want to buy a Lexus LS460 or IS-F when the Tundra Pickup uses a DOHC V8?

Nah... the Northstar has too much negative baggage associated with it -- a spotty reliability record with earlier renditions and a mediocre performance throughout its life. I am not sure anyone ever revered Northstar or was impressed by its performance. Although it was a decent enough engine it was never truly impressive in any way. If they want to name their V8s and stick to the same theme, try Polaris. It means North Star and it is the US's first submarine launched nuclear ballistic missile.

Base on that reasoning the CTS-V is no more than a 4-door Camaro ZL1 and the CTS-V Coupe is a Camaro! Oh, actually, its worse because the Camaro actually has more power (580 vs 556), so who will want to buy a CTS-V for $15K more money? Well, it's not the same because the Camaro is a car with a low rent cabin and appeals to the performance affectionados on a budget. The CTS-V is a posh performance sedan which caresses the owner with luxury while it delivers supercar performance. I for one will not consider a Camaro ZL1 because I don't want to live with the cabin. The ATS-V and the next Camaro SS having the same engine? That's all well and good by me. It's fine even if the Camaro gets a slightly more powerful tune because it has less civility and noise concerns. Avoiding sharing the powerplant with a less prestigious brand's product is a lousy excuse to adopt an inferior engine and accept reduced performance. If you do a TT V6 chances are you will at best reach parity with whatever M3 is on the way. A Pushrod V8 allows you to exceed the power output of an M3 while incurring less mass penalty. This is not an advantage you want to throw away. The other thing is differentiation. Anyone who is looking for parity with an M3, or subscribe religiously to the DOHC Bi-turbo = desirable view on cars will buy an M3 before he'll buyer an ATS-V. Anyone who is looking for a uniquely American luxury sports sedan with a throbbing V8 and totally lag free power will look past the ATS-V to either the CTS-V or, if they can't afford it, pinch their nose and buy a Camaro whose level of appointments frown upon. You may end up getting neither the mis-informed DOHC worshipper nor fan of American Muscle looking for a luxurious ride.

No... you put the Naturally Aspirated V8 in the ATS-V and the Supercharged V8 in the CTS-V. The ATS-V gets a "regular" Corvette derivative engine whereas the CTS-V gets the Corvette ZR1 derivative engine. Simply mapping a 7.5% improvement in output due to direct injection, this pegs the ATS-V at 470hp and the CTS-V at 600 hp even assuming a displacement of 6.2 liters. Fuel economy will be around 17/26 for the ATS-V assuming a 6% improvement in fuel economy from DI and AFM -- which is a little conservative considering that the heavier and less aerodynamic Camaro SS is already at 16/25 with the 6-spd Auto. This compares favorably with any other alternative powerplant configuration that produces 450~500 hp. As far as balance goes, a pushrod V8 has the advantage of being lighter than a bi-turbo V6, so it puts less weight up front. It is also easier to fit in the engine bay because it is roughly as long as the 2.5 I4 and no wider than the 3.6 V6. An LF3 (3.0 TTV6) on the other hand requires a complex arrangement of ducting to the turbos, from the turbos to one or two intercooler(s) ahead of the radiator and more ducting from the intercooler(s) to the intake plenum. Despite the lower output, the ATS might be faster (especially to 60 mph) because it is lighter and the CTS-V's performance is largely traction limited. This is as much of a problem as the fact that the M3 is faster than the M5, and the C63 is faster than the E63 -- which really isn't a problem for either BMW or M-B.

The 4.2 had so much potential and was such a smooth engine -- more so than the V8s -- it was hard to see it go. A big displacement six would be an interesting alternative to a V8 in luxury cars although the length of the engine will be problematic. The thing about an I6 is that it is naturally balanced. So, while V6s and V8s get progressively less refined as they grow larger in displacement, Inline-6s don't. The same thing can be said of H6s and V12s but those are even more problematic from a packaging standpoint. The downside of course is that Inline sixes are heavy and excessively long, this led to the dorminant majority of automakers going to harmonically imperfect but more compact V6 and V8 configurations. Inline 6s scale very well with displacement. You can have a completely smooth running 11 liters Inline 6, you can't say the same of V6es and to a lesser degree V8s. A 4.2 liter or 5 liter Inline-6 will actually be smoother than a V8 of a similar displacement. Plus, because it doesn't need the heavy counter weights of the 90 deg X-plane V8 it is more responsive to throttle inputs.

[Quoting the Autoweek Article] Is there an ATS coupe or V-spec in the future? "It's a fair assumption that those are two directions we'd like to take," Butler says with a smile. The more pressing question might be what would power the ATS-V. It almost certainly won't be a small-block. Read more: http://www.autoweek....2#ixzz22FZuG7Fk I won't put too much weight on that statement. It is not Butler's response, it is the journalist's opinion. And, it is backed up by absolutely nothing in the article or any official release. Fact is, a NA V8 will slot well into the ATS -- given that the CTS-V has a Supercharged V8. It'll be similar in positioning between say a C55 and an E55 with the latter getting a forced induced M113 5.4L V8, while the former gets the NA version. A 6.2 Small Block weighs less than a bi-turbo 3.0, cost less and will be 50~70 hp more powerful. The engine will also be essentially a parts bin item from the C7 Corvette so development costs are sunken whether it is utilized or not. Fuel Economy arguments in favor of a Turbo V6 is shaky at best and any CAFE concern makes as much sense as a trying to measure the rise in the water level of an Olympic size swimming pool when you empty a mug of coffee into it. The technical case is in favor of the Gen V V8. If GM opts for the LF3 (Bi-turbo 3.0) engine it won't be because of the technical or performance merit. It will be because of a desire to differentiate the ATS from the legacy performance vehicles from GM such as the Vette, the Camaro and the CTS-V. In anycase, the Gen V is out of the bag... at least the truck version is. Here is a photo of a bonafide Gen V Small Block V8 at GM's factory. No specs, no details, nothing. And, I'll leave it to everyone to draw their own speculations regarding the features on it.

Not the 458. The California is 3800~3900 lbs, but that is more a Grand Touring car that an outright performance model.

Just drill a hole in the bottom of it to allow the fluids to drain?

I don't think that's the LMP... that is the Cien concept coupe. Anyway, the point is that if you spend $80K on a composite monocoque, power it with a $15K DI-VVT (Gen V) V8 engine and a $10K Getrag 7-spd DC transmission. You can have a $150K car in the 2,700~2,800 lbs class (about 200 lbs less than the C7 vette) with about 550hp and 500 lb-ft. All you have to do is compare that to the 3,200 lbs Ferrari 458 with 562hp and 398 lb-ft. Such a car has the potential to be play with and beat with the best the world has to offer in every performance respect. That you won't sell a lot of such cars really isn't a problem as long as you develop it and build it in a manner that requires a large run rate to break even and be profitable.

A V12 is all the more attractive if everyone else is moving away from it. Rarity = exclusivity = desirability. While force fed V8s may have better fuel economy, fuel economy by and large is not important in this category. It's not important because the category of buyers shopping for a supercar or a flagship ultra-luxury sedan doesn't care about fuel economy. It is also not important because the tiny volume of cars sold in these categories also means that whatever the fuel economy numbers are like it won't even register in the 5th significant digit as far as CAFE goes and only the 3rd sig fig matters for the purpose of penalties and published ratings. What's important is that the buyer has to believe that this is an over the top car with over the top performance and it's something that very few individuals can afford or obtain. In fact, a 14 liter V16 made from siamesing two small block V8s will be even better. At 1100 hp normally aspirated it'll also give you all the bragging rights you need. The problem being that such an engine will be pretty darn long and may be a liability from a packaging and weight distribution standpoint, that's if you can find an available transmission for it. Besides, a V12 is naturally 100% balanced; a V16 is not.

SAE-certified at 259 horsepower (193 kW) and 260 lb.-ft. of torque (353 Nm). Its peak torque is sustained from 1,700 to 5,500 rpm Technically, that's impossible because 5500 rpm x 260 lb-ft / 5252 = 272.2 hp

The other thing they can do is to build a V12 GT car based on the C7 Platform but with Caddy's unique sheet metal. In this case the expenditures will be mostly on the V12 powerplant instead on the chassis. The most straight forward path to a V12 is to cast a block that is essentially two 3.6 DI V6 mated end to end to form a 7.2 liter 12-cylinder mill. Such an engine will make ~640 bhp and 550 lb-ft. Sharing the valvetrain components, rods, pistons and combustion chamber design which minimize development and tooling costs. The same Getrag 7-speed Dual Clutch auto can be sourced. The car will probably be somewhat on the heavier side (~3500 lbs) although still pretty darn decent compared to the porky competition given that the Vette platform is extremely mass efficient. Ultimately though this will be a different animal with a focus on V12 clout and grand touring grandeur rather than outright performance. It won't beat Ferrari, it probably won't even match the ZR1 in sheer performance, but it'll make Aston Vantage buyers think twice. The upside to this approach is that it'll also create a befitting engine for whatever large sedan flagship Caddy has in mind. Such a vehicle would probably use the LF3 3.0 Bi-turbo V6 as the entry engine, possibly a Gen V pushrod V8 as the mid-level choice with the V12 as the top tier option. A case can even be made that with the V12 the V8 can be bypassed altogether with practicality and fuel efficiency oriented buyers being steered towards the TT V6 while buyers while those wanting an over the top car gets the V12. Without a V12, the top tier engine will likely be a supercharged pushrod V8 which may not carry as much desirability as refined 12-cylinder engine.

Should Cadillac do a carbon fiber monocoque supercar with an American twist to rival the Ferrari 458? Such a vehicle will also put Caddy in the same field as the McLaren MP4-12C, Lamborghini Gallardo, Lexus LFA, Porsche 912, you name it). This will be a small volume vehicle probably around 2000 units a year and the carbon fiber chassis will probably be outsourced. It'll sell for around $150K. What GM has that the world doesn't is the light, compact, powerful and efficient small block V8. Unlike all the aforementioned cars, the Caddy will save a lot of money on powertrain development allowing it to spend more on the chassis and other finishings while selling the car for roughly 50% more than the ZR1 and about half what the competition is asking. The target parameters are very achievable at 3 times the Corvette's budget. 2-seat, Mid-Engine, Rear Drive 2800 lbs Dry Weight (est 200 lbs less than the Corvette C7) Carbon Fiber Monocoque Central Tub (Outsourced; possibly to McLaren) 7.0 liter Gen V Pushrod 16-valve V8 w/ DI & VVT (Est. 550hp @ 6800 rpm, 500 lb-ft @ 4800 rpm, 7000 rpm max) 7-speed Dual Clutch Gearbox (Getrag -- 7DCL750 w/ 553 lb-ft max input torque) Coil Springs, Double Wishbones, Magnetorologic shocks Goodyear Eagle F1 Supercar G2 Run-on-Flat tires (Front: 265/40 ZR19 / Rear: 325/35ZR20) 0-60 mph 3.0 secs; 1/4 mile 10.9 secs; road holding 1.10 G; 15 (City) / 25 (Hwy) mpg Street creds for Caddy, plus homoglation for GM racing.

No, but they do not view the V8 negatively compared to a turbo V6 either, especially when power output is comparable or superior. If a V8 can be similarly or more powerful, cost less, be less demanding on maintenance, and offer similar fuel economy, there is very little imperative to downsize displacement and go with forced induction. The big misconception is that there is a huge fuel economy difference between a 3.5 TTV6 and a 6.2 Pushrod NA V8. There isn't. An SHO Taurus is at 17/25 mpg, A Camaro SS is at 16/25 mpg -- both automatic. By itself, the V8 6.2 is actually lighter than the TT V6 3.5, with less plumbing under the hood and cost less to build. It makes 35 more hp and 50 more lb-ft of twist. That's without direct injection and closing that 1 mpg gap shouldn't be mission impossible.

I don't know where the idea of a "Flagship" ever got associated with the XTS. GM never made such a claim or suggestion. The layout, size, powerplant and everything else about the car yells "Lexus ES350". That's not a bad thing, the ES is a huge seller and this can be Cadillac's volume driver. But that has nothing to do with a Flagship.