dwightlooi

The Chevy volt is a nice technological exercise, but in practical terms there aren’t that many people who want to spend $40K to save money on gas with a plug in vehicle. Not that many wants to pay higher taxes so government can subsidize it either. If you set aside the plug in aspects of the vehicle and just consider its IC-electric efficiency, it is not very impressive. The Volt manages 35mpg city / 40 highway on its 1.4 liter engine, electric motor and whatever energy regeneration through braking it can achieve. That’s worse than the Prius (51 / 48), the Insight (40 / 43) or – in terms of the highway numbers – the Cruze Eco (42). This, quite honestly, is not that stellar. Part of the reason for the Volt’s inefficiency operating as a strict gasoline electric hybrid that fact that it is a very heavy vehicle weighing in at close to 3800 lbs typically equipped, of which 435 lbs is the huge battery it lugs around all day. The very concept of a series hybrid is also less efficient in gasoline electric mode given that you have generation loss and motor conversion loss which – in total – is higher than if the engine drives the wheels mechanically. So, how will you build the non-plug in vehicle with the ultimate MPG numbers? Here’s my formula for a Cadillac or Chevrolet “Hypermiller’s Special” that is both the MPG king and at least a match for the CRX in terms of driving excitement. First, you get rid of 1200 lbs. The platform is basically an Aluminum Kappa with the engine in the trunk, battery in the nose and fuel tank in the tunnel. The body is shaped to deliver a 0.25 Cd with a boat tailed profile, full underbody tray and fenders covering the rear tires. The battery consists of 2 of the Volts’s 9 modules and packs 3.56 kWh – this is 22% the Volt’s capacity, but twice the Prius’s. Unlike most Hybrids, this one is Diesel-Electric not Gasoline Electric. This is mated to the same 55kW generator-motor in the Volt, but the 111kW main propulsion motor is ditched. This is not a CTS-V, but at 2500 lbs and 150bhp of combined diesel-electric power, it’ll hang with a Miata on the straight away or in the twisties while turning in 70MPG and comfortably seating two. It’ll have as much luggage space as a Fiero using the same arrangement of a small front compartment and a rear compartment accessed by opening the engine compartment lid. Vehicle: Cadillac EVS MRSP: $32,000 (before any subsidy) Layout: Mid-Engine, Rear-Drive Platform: Kappa Derivative MR platform Materials: Hydroformed Aluminum Frame Rails, Aluminum Body Panels, CFRP hood and engine compartment lid Body Style: 2-door, 2-passenger coupe; 0.25 Cd Curb Weight: 2600 lbs ICE: 1.0 liter DOHC 12-Valve 3-cylinder Direct Injection Turbodiesel w/ balancer shaft (based on 1.3 liter Opel CDTi engine) ICE Output: 75 bhp @ 4000 rpm / 120 lb-ft @ 1800 rpm Generator-Motor: 55kW Generator-Motor coupled via clutched Planetary (from Volt) Motor-Output: 75 hp @ 65 mph; 135 lb-ft @ 0 mph Battery: 3.56 kWh Lithium-Ion Battery Pack (two of the Volt’s nine 32-cell modules) Wheels: 17 x 7 Light Weight Forged Aluminum Tires: 215/45VR17 Goodyear Assurance Fuel Max Brakes: Brembo 2-piston floating calipers 11.3” vented Discs (front), 1-piston Sliding calipers 10.4” vented discs (rear) Fuel Type: #2 Diesel Fuel Capacity: 8.8 Gallons Range: 616 miles (San Francisco to Las Vegas on one tank of fuel with 7.5% reserves) Performance: 0-60 mph in 7.5 seconds Roadholding: 0.88 g Fuel Economy: 70 mpg (city) / 70 mpg (hwy)

Honestly, the ATS is a make or break deal for Cadillac's future and I'll rather see it 1 year late than 1 year immature. They have to get it right out of the gates.

Nothing jumps out as being wrong or out of place. No gimmicks like the fake vents on the Buicks, no dubious fanny packs on the trunk like the first previous 7-series, no clutter on the flanks. I'll reserve judgement until I see the whole car from all vantage points. But so far, no red flags. Now if GM will only... Keep the base curb weight under 3500 lbs Come up with an 8-speed or a wide ratio 6-speed Stuff further refined versions of the 2.0T, 3.6 and 6.2 power plants in there Keep it all variants in the 30~45K bracket They'll have a winner.

X3 28i is 19/26 X3 35i is 16/23 Why? Gear Ratios, gear ratios, gear ratios. The BMW's ZF 8-speed tranny simply has a taller top gear.

Let's get one thing straight... Companies should not be in the business of "creating jobs". Companies should be in the business of turning out products or services which the market demands and make a profit. Job creation is incidental to manpower requirements necessary to fulfill the profit motive. Herein lies the folly of Unions. Unions -- by definition -- are anti-competitive organizations whose purpose is to extort compensation and benefits above and beyond that which a competitive labor market will bear via the threat of work disruption, political lobbying or out right racketeering. Basically, Unions cause a scenario where companies -- under the threat of labor actions -- are forced into a substantially higher wage structure than needed find qualified and willing applicants to fill their human resource needs. This has three cascading effects. The first being that the companies -- sometimes an entire industry -- under the strangle hold of powerful unions becomes uncompetitive and are often forced into decline. These declining companies or industries, then either flee the state or country for alternative locales where there is a free market for labor, or (if they are unable to do so) simply fail and collapse. In the meanwhile, new companies or budding industries see what's happening and set up shop outside the beleaguered regions with strong union influence. In the end, entire industries and nations are decimated, able and willing individuals are unable to find work due to the outflow of capital, and an entire region repels capital and economic growth. The goal of trying to secure better rewards for their members, while noble from an idealistic sense, ultimately resulted in killing of the goose that lays the eggs. In fact, it often kills enough geese that the species become endangered or extinct.

V6es are a completely different ball game. You can build a 350 hp, direct injected, VVT and AFM equipped Pushrod V6 displacing 4.7 liters that has similar or better fuel economy than 323hp 3.6 liter DOHC DI V6. However, V6es are used in applications like Minivans, Family Sedans and any number of vehicles that are NOT performance cars. V6es are also used in luxury applications as the more economical, lower performing engine option. As such, being of a lower displacing to get in a lower displacement tax brackets is important. This is NOT important for a V8 engine which is always a deliberate choice made for performance or prestige.

I think the cost of developing a V12 can be quite minimal if you do it using existing V6 parts. Really, take two V6es redesign the block so they are joined. Keep the valves, pistons, rods, valve springs, cam phasers, lifters, combustion chamber geometry, intake ports, spark plugs and everything else as is. Two 3.6 LFX V6es make a decent enough V12 -- 7.2 liters, 646hp and 556 lb-ft if you let it spin to 6800 rpm. Still a good 600hp if you cap it off at 6200 so it can work with exisiting GM automatic transmissions. Either is more than competitive. No, it won't have "volume". But neither does engines like the LS7. In fact, it'll have better economies of scale because most of its parts are shared with ubiquitous 3.6 V6. To make it extra special, you can build it at GM's Performance Build Center at Wixom, Michigan it can then proudly where a plague saying... Hand Made in USA by John Doe Signature

I think you have enough materials for an alphabet soup as it is... SIBC-VVT-RRA-AFM-RHL-CNS V8 Single In Block Cam - Variable Valve Timing - Roller Rocker Arm - Active Fuel Management - Roller Hydraulic Lifter - Coil Near Spark V8

(1) Going to 3-valves requires either an SOHC design or a Pushrod design with two in-block camshafts. Both of which grossly increase the engine size, mass and complexity. And, really, 2-valve heads can already support 72 bhp / liter, 11:1 compression and a 7000 rpm redline with port injection and no VVT. Do we really need to grossly complicate things to improve breathing? (2) Using turbocharging and supercharging at the same time (ala VW/Audi TSi) is mainly a scheme designed to enhance low end torque and response in small displacement engines. The Small block V8 needs no help in this department. In fact, it may actually be better to lower maximum torque and move it slightly higher in the rev range. This actually improve traction off the line. Traditionally, cam grinds that do this would have resulted in a lumpy idle, but if cam-in-cam VVT is implemented some of the overlap can be artificially dialed out and much hotter cams can be made civil. Apart from that, I think your wish will be fulfilled. We know for a fact that the new Gen V Pushrod V8s will feature Direct Injection and variable displacement. We also know that it will have VVT and strongly suspect that it may be a cam-in-cam setup (ala Viper) which afford independent intake and exhaust timing control. This engine (or engine family) will propagate across the entire GM lineup that currently gets V8 powerplants. This will probably include the 2-mode Hybrids.

VW's W12 is not really a W12 in the traditional sense (ie. three 4 cylinder banks). It is really a V12 where each bank features staggered cylinders very much like bullets in a double stack magazine. Within each bank, the cylinders are spayed at 15 degrees (later reduced to 10.6 degrees), but the top of the pistons are flush with the deck and in parallel with the other row. Each bank has only one head with two camshafts. The camshafts are independent in that one only operates intake valves and the other only operates exhaust valves. They do so via long-short valve stems and asymmetric intake/exhaust valve angles. Half of the W12 is a 10.6 degree or 15 degree VR6. These are actually more of a staggered I6 than a V6. They have 7 main bearings (vs 4 in a typical V6) and they sound like a slightly off beat Inline-6 more than a V6. I had the first generation 2.8 liter 172hp, 12v version a long time ago in an 3rd Gen Golf GTi VR6 (1995 model). It's by far the most compact 12-cylinder design. It is however not the best flowing design or the highest revving design. It is also not a balanced design and there are no attempts to fully balance it with balancer shafts. Instead, each bank behaves like a slightly off-balance I6 and the mild residual vibrations are simply tolerated.

Well, let's recap why and how pushrod engines came about. Before there were Pushrod engines there were SOHC and DOHC engines. In fact, WWII fighter V-12 engines were mostly SOHC 4-valve and 3-valve designs; the German ones even had direct injection. But somewhere along the way, engineers at American car companies realized that a OHC layout and especially a DOHC layout is unnecessarily complex and bulky; especially in a Vee engine where you have two banks of cylinders. Complex because there are four camshafts and their associated bearings and sprockets. Bulky because all the four cams are carried on top of the heads at the extremities of a Vee making the engine very wide with a lot of weight in the heads. So they concocted a new arrangement where four head mounted camshafts are reduced to just one camshaft nestled in the otherwise wasted space in the valley of the engine block. Pushrods actuate valves via rockers in on the cylinder head. This makes the cylinder heads drastically smaller and lighter. It also made the engine more efficient because there are less parts rubbing around and making frictional drag. The Pushrod engine however did not really have ANY advantage in an inline-4 or six. These engines derives no width advantage from a pushrod layout and minimal height benefit. The only reason Pushrod 4s existed was because the companies built pushrod V8s and V6es, allowing cost savings from component savings. This brings us to Asian and European cars companies. These companies had their roots in post war recovery economies and in building small vehicles powered by small engines. These engines are usually 4-cylinder mill which eventually evolved to DOHC 4-valve assemblies in the 1980s. When they started to make bigger V6 and V8 engines, they went with valvetrain configurations they are most familiar with and one which they had raced with -- SOHC and DOHC designs. Meanwhile, American car companies languished in the 80s and 90s; going into a downward spiral not because of engine design choices but because of the flawed business model that somehow a US car company operating in a high cost labor market should compete by trying to be the price and value leader. Cost cutting, quality cutting, technology cutting and other bean counting to compete on price produced a couple of decades worth of vehicles with inferior quality, inferior technology, inferior reliability and inferior performance. This gave everything they made a bad reputation including their design choices. For ANY given power output target, a Pushrod engine will be of a larger displacement than a DOHC counterpart. However, it is also smaller externally and lighter because its heads are so much smaller. It is also more fuel efficient because its valve train is so much simpler with so much fewer frictional elements. Whatever breathing advantageous a DOHC engine has is mostly irrelevant to fuel economy because of three reasons. The first being that the volumetric efficiency advantageous of 4-valve DOHC designs come at higher rpms, not at lower engine speeds where both designs have excess airflow capacity. The second being that at part throttle, which is the condition engines operate in at cruising speeds and a city driving, the breathing superiority of an engine is intentionally choked off by the throttle body. Lastly, an engine with higher displacement also has more torque at lower rpms which is conducive to the adoption of taller gearing which then reduces the rate of aspiration. Coming back to your question... a pushrod 4 or Inline 6 is not superior to a OHC I4 or I6, period. There is not packaging or frictional advantages. A V6 and V12 will see the same weight and frictional benefits, but not as much size benefit because most V6 and V12s are of a 60 deg angle and not the wider 90 deg angle. V6es also generally fall in a class of engines where the buyers may still care about displacement taxes to a notable degree. Hence, a smaller displacement DOHC V6 may be a legislative advantage over a larger displacement Pushrod V6 or equivalent power which may be lighter and more fuel efficient. With V8s though, the 90 deg angle sees the greatest packaging advantage afforded by a pushrod arrangement. V8s also fall into a class of engines where the consumer is obviously looking for more power and performance at the expense of fuel economy or tax advantageous -- otherwise they would have bought the same car with a lower powered V6 which is usually also available. Hence, for V8s Pushrod designs make maximum sense. If the competition either does not see this or is technically and logistically unable to capitalize on it, that's their loss!

Here is the problem with your argument... I'll wager that 95% or more of the general public do not know what DOHC is. Of the remaining 5%, some of them will be smart enough to know technical merit when they see it, some won't. But whatever the split is within that 5% it is irrelevant from a sales and marketing standpoint. In the end the car will sell based on looks, interior quality, refinement, performance, fuel economy and value. It wouldn't sell on the alphabet soup on the engine cover or the lack thereof.

Actually, there is a big difference between the FWD-RWD debate and the IBC-DOHC debate. FWD is absolutely, positively, lighter and more efficient. You throw away the drive shaft and rear axle saving about 50~100 lbs in mass. You decrease drive train loss from about 15% to about 10% by eliminating the friction from all the eliminated components. The debate has been about whether the way FWD changes the handling of the vehicle is worth the benefits. DOHC is not lighter, smaller or more efficient than Pushrods. It creates a bulkier, heavier engine with higher frictional losses. What it does is allow for more horsepower at higher RPMs in an engine of a given displacement. Apart from that, it is an inferior design for a Vee-type engine. Inferior because heavier, larger, higher fuel consumption and less power is inferior. An example is... BMW S65 4.0 DOHC V8 -- 202 kg engine weight -- 414 hp / 295 lb-ft @ 14/20 mpg -- 3700 lbs M3 w/6-speed manual GM LS3 6.2 Pushrod V8 -- 183 kg engine weight -- 426 hp / 420 lb-ft @ 16/24 mpg -- 3860 lbs Camaro SS w/6-speed manual You don't have to try to sell pushrods. All you have to do is sell on the superiority of the vehicle and the valvetrain becomes irrelevant. If you have an ATS-V that has 470hp, 440 lb-ft and 25mpg highway. You won't have to "try" to convince anyone that the Pushrod engine is superior. And, these are extremely conservative numbers -- they assumes that the new Gen V Small block with Direct Injection, VVT and AFM will be no more than 7.8% more powerful and 4% better in fuel economy than the current LS3 V8. Global Warming and carbon footprint being important is complete and utter rubbish. But, let's say you care about that... 25mpg is 25mpg. 25mpg = lower "Carbon Footprint" than 23 mpg, period. Carbon footprint is not dependent on the displacement of the engine or its valvetrain configuration. It is dependent only on the amount of gasoline you need to burn to go a given distance.

Well, following flawed popular opinion in defiance of the technical facts and merit is not a good strategy. A good example is the 1.4T in the Cruze. Losing a third of the displacement and adding a turbocharger resulted in an engine that is both expensive and worse in fuel economy than competing 1.8 and 2.0 liter NA engines in the same or slightly superior power class. Wanting DOHC for the sake of the alphabet soup is more like saying you want the BMW grade interior but not an even better interior, because it is a grade BMW interior and people expect it. I don't think most consumers care about DOHC at all. They do care about performance, refinement and fuel economy. Show that you can do all that better than the competition and your choice of valvetrain layout won't matter. In fact, do that and sustain that for a generation or two and you'll have gear heads demanding, compact, lightweight and efficient pushrod engines.

I think we just have to agree to disagree on this. I believe that GM needs a stellar 3.0~3.6 liter class DOHC V6 and DOHC I4. For the V8 realm, however, pushrod engines provide more power, more torque and lower fuel consumption at a lower cost for any given external dimension or engine weight. This makes it technically the superior design choice. A Pushrod arrangement also makes the cars it powers more differentiated, more uniquely American, in a market place crowded with DOHC V8s. The downside is that it will sport a larger displacement, and that does not endear it to various racing class rules or displacement tax brackets. This downside is not, however, particularly relevant for a V8 engine given that buyers who elect to buy a V8 model probably does not care about the displacement tax as much as the performance of the vehicle. Otherwise, they can and would have picked the V6 variant of the car instead.

Not really, it's still a 96mm bore center Ecotec block with DOHC, hydraulic VVT, roller followers, hydraulic lash adjusters and Direct injection. The biggest change comes from an increase in stroke from 98mm to 101mm. This affords it 190hp and 180 lb-ft, an increase of 8 hp and 8 lb-ft over the current Direct Injection 2.4 (LAF).

I don't think there is any major architectural changes coming in the next 5 years for GM's Direct Injected DOHC I4 and V6 engines. We may get different tunes of the current lineup -- different tunes that are either intentional or incidental to the installation of these engine into various new models -- but that's about it. I don't see new bore centers, changing the bore x stroke dimensions, switching from DOHC to SOHC, adding a new VVL valvetrain or making HCCI a reality. The recent changes to the 4-cylinder -- LNF to LHU -- for instance is really a manufacturability change. GM went from a lost foam casting to a sand casting for the block. The changes to the V6 -- LLT to LFX -- while it improves performance by about 15~19 hp and supposedly enhances NVH, the main reason for the changes is also manufacturability. GM went from a conventional head with an exhaust header to an integrated exhaust collector which then eliminate the need for an exhaust header altogether.

All the right bits are in place for the ATS. Power train wise, GM will have a more than competitive 2.0T engine, 3.6 DI V6, DI Smallblock V8 and, if you really want, a 170~190hp 2.0 turbodiesel for our European friends to tap. Platform wise it'll be something smaller and light than the 3900 lbs Zeta. How much lighter might be subjected to debate, but even if its on the porky side at 3600 lbs it won't be a deal killer. It all comes down to the execution now... and as far as that goes the jury is still out. Yes the ATS look like the first real effort that would address the Global market. If and when they go back to Europe they will need s diesel and I am sure one will find it's way in. The engines you are juggling here are good fodder but I suspect we have yet to see what engine GM will really have. I get the feeling many of the engines you have mapped out may not even be in play and will be updated or replaced with other plants. The Eco is evolving now, The HV V6 will also see changes. The V8 pushrod is getting some major changes that GM has not even fully outlines and only hinted at. I also suspect we will see a small DOHC V8 to fill market needs in global markets. You can play with numbers all you like but most buyers expect these engines. Even with the Pushrod engine they really need to market the advantages and give the Cadillac their own tunes and trim. I would love to see the engines dressed in Aluminum covers and even billet parts with stainless trim. At the very least powder coated vs the plastic covers. The owner of a Cadillac should be proud to open the hood, trunk and interior to show of his car and its quality. It was details like this that made it a standard others were judged by. Even my Fiero came powder coated red covers and intake with Stainless 12 point fasteners. Cadillac should get no less. Actually, I do not expect much changes to the 2.0T and the 3.6 V6 between now and the ATS's launch as a 2014 model in 2013. The 2.0T just went through a major revision from the LNF to the LHU. The 3.6 just got revised this year to the LFX.

All the right bits are in place for the ATS. Power train wise, GM will have a more than competitive 2.0T engine, 3.6 DI V6, DI Smallblock V8 and, if you really want, a 170~190hp 2.0 turbodiesel for our European friends to tap. Platform wise it'll be something smaller and light than the 3900 lbs Zeta. How much lighter might be subjected to debate, but even if its on the porky side at 3600 lbs it won't be a deal killer. It all comes down to the execution now... and as far as that goes the jury is still out.

Existing on the backs of a few models is not necessarily a bad thing. It sure as hell is better than a dozen and a half models 3/4ths of which don't sell.

I don't think Cadillac's priority should be to flesh out a big line up that matches the competition or to return to Europe. There isn't enough money or resources to do either of that overnight or in a couple of years. The priority should be to be successful and profitable in every model that they launch. This means focusing on the ATS and focusing on the key markets they have profitability and penetration in -- North America and China. Once you have a solid footing and a solid revenue profit stream there will be the funds and resources to grow -- but not before.

Yes, turbo-electric drive... The Volt is pretty close in series mode... the only thing being that it doesn't have a diesel engine. It is not very sleek to the wind. It is really heavy. And, it is carrying around too much battery because it wants to be a plug in. If you really want a Hypermiller's special, here's the recipe:- 1st Generation -- Turbo-Diesel Electric Drive 2500 lbs, 2-door, 2-seat coupe Aluminum Spaced Frame, Fiber Glass Reinforced Plastic body panels 0.25 or better drag co-efficient + Low rolling resistance tires 1.0 liter 3-cylinder Turbo-diesel Generator (60 bhp) 110 kW Permanent Magnet Electric Motor / Recuperation generator (149 bhp) 4 kWh Li-Ion battery (Up to 8~12 miles on electric power) 0-60 in 7.5 secs, 60 mpg (City) / 75 mpg (Hwy) 2nd Generation -- Combined Gas & Steam Electric Drive + Advanced Materials 2000 lbs, 2-door, 2-seat coupe Aluminum-Lithium Spaced Frame, Molded Carbon Fiber Reinforced Plastic body panels 0.23 or better drag co-efficient + Low rolling resistance tires 40 kW Gas Turbine Generator + 12 kW Steam turbine Generator* 110 kW Permanent Magnet Electric Motor / Recuperation generator (149 bhp) 4 kWh Li-Ion battery (Up to 8~12 miles on electric power) 0-60 in 7.0 secs, 80 mpg (City) / 100 mpg (Hwy) * COGAS-E uses a gas turbine as the primary generation source while capturing most of the exhaust heat with a heat exchanger that boils distilled water. The generated steam is used to drive a close cycle steam turbine coupled to a secondary generator so very little energy is wasted. Because the two generators do not run at the same speed or is responsive to instantaneous power demands, the only way to have a drivable vehicle is to utilize a fully electric drive. COGAS-E is currently the most efficient way of making power both in power stations and on large marine installations like cruise ships.

Well, I think that it'll be nice for Cadillac to offer diesels, but I don't think should be a priority -- at least not for the USA. From a revenue standpoint, from a brand development standpoint or from an image standpoint. It just isn't that important. What's more important is getting the ATS out, and getting it as polished as they can from the get go. That, followed by a CTS follow-on and a large RWD flagship. Offering diesels is one of those things that can happen if and when they get around to it.

The economy of a diesel engine is the result of four things:- (1) Diesel fuel has a higher energy density. A gallon of diesel is worth 136.3 MJ of energy vs 122.3 MJ for gasoline. Hence, assuming the same exact conversion efficiency from chemical to mechanical energy, you'll need to burn 11.3% fewer gallons diesel fuel to get the same work done. A similar thing can be said of gasoline vs ethanol. Everything else being constant, you need to burn 30% less gasoline than ethanol to get the same work done. (2) Gasoline engines are throttled by the throttle body. At cruise, the engine is intentionally choked to a fraction of its volumetric efficiency by the throttle body. Less air is ingested into the engine, while the fuel injectors open for a shorter duration so less fuel is burned. The end result is stoichiometric or near stiochiometric combustion every time, all the time. It also means that the engine is constantly working to suck air through an intake obstruction -- an activity that results in a parasitic loss. Diesel engines don't do that. Diesel engines do not have a throttle body. Instead they suck in the maximum amount of air all the time. Power is regulated simply by introducing more or less fuel. The engine runs lean at low rpm cruise, it runs rich if you floor the pedal. This means that there is less pumping losses at cruise and superior efficiency. However, it also makes emissions trickier to manage -- running lean produces a lot of oxides of nitrogen (NOx), running rich produces unburned hydrocarbons. Diesel engines have to resort to nitrogen storing catalysts and/or Urea (yes, like in urine) injection to stay within modern emission standards. Bluetec is really a nicer name for "Mercedes Piss Injection". (3) Diesel engines also do not use a spark plug. Instead they compress fuel to between 16:1 (turbocharged applications) to 22:1 compression. At a critical pressure, the fuel air mixture spontaneously ignite. This is more efficient in two ways... higher compression itself leads to superior combustion efficiency. Spontaneous ignition releases the energy more quickly and throughly than a spark inititated flame front taking its time to propagate through the combustion chamber as the piston is going down. (4) Finally, diesel engines -- especially turbodiesel engines -- make a disproportionately high amount of torque for their given size or power output. A 170 hp gasoline engine will typically have about 140~150 lb-ft, a turbocharged one with 170 hp might manage 200 lb-ft. A 170hp turbodiesel will typically make close to 300 lb-ft. Diesels also hit their torque peak very low in the rev range (1200~2000 rpm). The high torque to power ratio of the diesel engines along with their low torque peaks are conducive to very tall gearing. This means a lower cruising rpm and superior efficiency. So what's bad about diesels? Well, they are noisier. They have a very low rev range meaning they like and need a lot of gears (compared to their gasoline counterparts). They are either dirtier or require more elaborate and expensive exhaust emission hardware. They need very strong bottom ends to deal with the constant "knocking" at lower rpms, this makes the engines heavier. They need a turbocharger to match the power output of a comparably sized gasoline engine -- again, more complexity, more cost and more articles to maintain. On top of that, they have to deal with a gasoline centric infrastructure and a frequently unfavorable consumer opinion in the USA.

The problem with diesel in the USA is threefold... (1) Historically, and still largely true today, buyers perceive diesels as being less refined than gasoline engines. There is actually some validity to this even though the diesels of today are a lot better than those of yesteryear's. Being a compression ignition engine means that you basically cannot control when the ignition of the mixture occurs. Ignition occurs after a given amount of time at a given pressure instead of being a timed event initiated by the spark plug. Hence, if ignition occurs right at top dead center at 3000 rpm, it'll happen before top dead center before 3000 rpm and after top dead center after 3000 rpm. The occurrence of ignition before the piston reaches the top of the stroke is why diesels clatter like they are in a perpetual state of knocking at idle and at lower rpms. The occurrence after the piston has past TDC and is already on the way down is also why diesel engines lose power quickly at higher rpms. DI can mitigate this somewhat with timed and multiple injections of fuel, but emissions and the basic mechanics of an ignitable mixture places limits of what can be done simply by regulating fuel supply. (2) Diesels are also slightly inconvenient because the USA gas station infrastructure is such that between 1/2 to 4/5 of gas stations do not sell diesel fuel. This means that you cannot count on being able to refuel anywhere and everywhere, but must take the effort to remember or search for diesel selling stations. (3) Finally, diesels cost more. About $2000 more than the gasoline counterparts. Traditionally, US car buyers are willing to pay more money for a vehicle to go fast, or to get a greater degree of refinement. They weren't eager to pay more to save on fuel. This is because fuel was historically cheap in the USA -- cheaper than drinking water. Even today, at $3.50~$4.00 a gallon it isn't all that expensive. It takes about 5 years to break even on the price premium of a diesel vehicle and about 11 years to break even on a Hybrid. There are, and have always been, a sub-set of "green" buyers, but they are a small minority. Also, the "green" set buy Priuses not diesels -- partly because it is gives them more "green" creds amongst their "green" buddies. Notice that I said Prius and not Hybrids in general. This is because part of the equation is to be seen as "green" and only the Prius gives that instantly recognizable green creds; they don't buy a Ford Fusion, Honda Accord, Toyota Camry Hybrid because these are not instantly recognized as a Hybrid. This is why Prius sales exceed all these other ones combined. In short, the notion of paying more -- about $2000 more -- for a slower, noisier vehicle you cannot fill up at EVERY gas station so you can save about $400 on the average $1600 annual year fuel tab, never really caught on.