k-mart wrote:Mack, I'm not so sure you want to get into an arguement over fuel economy with LSX owners.
First off, it's not an "argument", it's a discussion
k-mart wrote:I'm trying to decide which BMW, MB, and Lexus to compare with my technologically archaic 2000 C5 'Vette. I guess I'll stay within the sports car category, which helps most of the import causes, btw.
Let me give you a baseline for my personal experience. 19-22mpg city and 30-34mpg highway.
I'd be excited to see those numbers reproduced on a wide scale. I would venture to say that your performance is exceptional, given the rating of 17-18 city and 25-27 (coupe and convertible). But then, you're not basing any of your comparisons on their performance, right? You're basing them strictly on their ratings. Not entirely fair, but let's move on.
k-mart wrote:Take, for example, the BMW Z4 M Coupe. It has less horsepower, a much less torque, and weighs nearly the same as my C5. Yet, it gets only a rated 16mpg city and 26mpg highway. Not quite up to snuff and we'll not get into the performance vs. price category.
Where did you find these erroneous numbers? I show (from Edmunds) that it's rated at 20/30. That's higher than your Vette, BTW. True enough, the weight is very close, but the engine difference is tremendous. I tried to keep my comparisons close to size, but let's move on again.
k-mart wrote:Now, lets consider the $95k MB SL550. It makes nearly as much power as a C6 and should give my C5 a run for its money in straight line performance. Oh, wait, my car should beat it to 60mph by at least 1/2 of a second. It gets better. Only rated at 14city and 22highway. You're right. Those OHC's are such a technological revolution! Ohh.....wait, I just saw the SLK55 AMG. Surely this one can give the LSX a run for its money. Nope.....16city and 22highway......damn those crafty germans......
The SL550 is not really a fair comparison, as it's not really in the sports car class. It's a roadster, but I digress. It's also over 1000 pounds MORE than your Vette. Fair? Hardly. Why not compare the CLK that is a little lighter (but not much) and is a coupe that is more designed for sport. Don't think that's fair? Let's look at the numbers, maybe you'll agree my comparison is a bit closer than yours -- Vette (CLK) length: 179.7 (183.2), wheelbase 104.5 (106.9), weight 3246 (3719). The SLK is 178.5, 100.8, and 4065.3 lbs. I think you'll agree that the CLK is closer to the Vette. If you wanted to step up to the SLK55, that one's even worse, at a hefty 4318.9 lbs. Ah, but comparing the CLK makes it a better discussion. Here's why - the CLK gas mileage, with the same 5.5L engine as the SLK gets 16 and 23, respectively. Oh, but it's 500 lbs more than the Vette. Kinda makes 17 and 27 from your Vette not look very remarkable. If we were to take the increases we saw from dropping 600 lbs (SLK down to CLK), 2MPG city and 1MPG, and tack them on, we would be at 18 and 24. Yes, not the same as the Vette, but the CLK also would have more power by over 10% (382 vs 345), more torque by over 10% (391 vs 350), and still have a smaller engine (5.5L vs 5.7L) than your Vette. One last little tidbit...the torque from the 5.5L comes a full 1600 RPM below where your Vette makes it's highest number. And 2000 RPM below where the brand new Z06 makes it's number, which is also lower (it has 385). Hmmm...did you say crafty??
k-mart wrote:Now we come to Lexus. This is the brand that most closely approaches the LSX in fuel economy at 21city and 28highway for the IS350. Congrats to them on that achievement a full decade after the C5 debuted, but that overdrive gear is a thing of beauty. 1600rpm at 70mph on the higway is great.
I realize that I've picked and chosen the cars here, but if you can give some better examples of performance per mpg, I'd love to see them. I also understand that my C5 isn't a GTO. The goat isn't far behind in the fuel economy or performance area, however.
Hmm...the Lexus seems to be close, except it's 300 lbs more and 2 full liters less engine. Ah, but it makes 306HP from
that 3.5L engine while still getting better gas mileage ratings than your lighter Vette. But, why not examine the new LS460? At 4332.1 lbs, it's the heaviest dog in the pack, but yet it gets better
ratings than your Vette for gas mileage in the city (19), and the same on the highway (27). Oh, but it's only 4.6L, and it makes more power than your Vette. Yes, not a sports car in any sense of the word, but shouldn't the TREMENDOUS weight advantage of 1100 lbs translate to vastly better fuel economy for you? Or would you prefer to look at the new Z06 that lost another 111 lbs from yours and is rated at only 1MPG more on the highway? 5 more HP and 18 more lb/ft of torque, but it's a full 1.1L more than the Lexus. Hmmm...crafty indeed. What do you think might happen when that engine makes it into the GS and SC's? Bet it gets pretty damn interesting when the 500lb lighter SC gets 400 HP (that's the projection when the 4.6L moves to those bodies) and 400lb/ft of torque. Talk about a far more fair comparison, the SC weighs more, but is 1.4 inches shorter (WB) and 1.2 inches shorter (length) than the Vette.
k-mart wrote:Obviously, its not about peak HP numbers. Especially when fuel economy is thrown into the equation.
I wasn't speaking solely on peak HP, I was speaking on the fact that newer engine technologies are bringing things up in the fuel economy and
HP range, while bringing size down. Heavier and safer (not comparing it to the Vette per se, just in general), and yet they get more miles and more power. Not a bad trade off.
k-mart wrote:You won't find a lighter, more compact, more fuel efficient, and more powerful motor than the old-fashioned push-rod Chevy V8.
I would whole-heartedly disagree, and I proved it. Your 5.7L engine makes less power than the new 4.6L Lexus engine, and with worse rated fuel economy. I have to go off rated because the Lexus might, like you've observed with your Vette, have better performance. True enough, the 5.7L is an older engine, but the 6.0L Chevy V8 in the Cobalt is newer, and gets horrendous gas mileage while making roughly the same power. I'd gladly trade 20HP for 10 (or more) MPG on the freeway. Oh, but take a look at something before I go...the Lexus weighs 600 lbs more than the Cobalt, but still gets that. Damn those crafty Japanese...