How About That, 2014 Corvette Gets 37.3 mpg

[cbaber]

Originally Posted by serialk11r

Technically I did, I mentioned that Porsche can do better (or at least match the Vette) with the same HP. Hah. The 2.7L DFI Cayman gets almost 40mpg doing 70mph, which I find extremely impressive considering how high the rolling resistance is on the stock tires. A Prius gets what, 50 at 70? Around town the Porsche is rated higher EPA despite not forcing a 1-4 shift or having a strange shift schedule.

I want to like the Corvette but I just can't get over the pushrod V8, whose <7k rev limit is kind of lame. Now that other manufacturers are coming to their senses and offering taller gears, Corvette fuel economy is no longer best in class.

Keep in mind the C7 has much more power, and over double the torque of a Cayman. It has double the displacement, and still gets the same fuel economy. That alone is pretty impressive, IMO. How high the motor revs is simply due to the displacement. The motor doesn't have to stretch out as far to develop power because of the large displacement. The 2.7 needs aggressive tuning to reach ~300 HP, and that requires a higher rev range.

Think of all the small displacement motors that develop a lot of power per liter. The F20C out of the AP1 Honda S2000 develops 240 HP from 2 liters, but requires 9k RPM to get there, with low torque. Due to complains about unusable power they had to tone it down to 8k RPM with the same HP output, by increasing displacement to 2.2L in the AP2 S2000.

I'd still rather have the Cayman, but only because there are too many Corvettes on the road lol

[Xist]

I do not pay much attention to powerful cars, although I remember being impressed with the S2000's power-to-liter, my 2L Prelude had 110HP! Unusable power? Didn't the audi TT have simliar power?

The Cayman? That is the Porsche designed by someone who really liked Dove soap?

I will get back to posting random thoughts on Facebook with zero friends...

[jamesqf]

Originally Posted by cbaber

Keep in mind the C7 has much more power, and over double the torque of a Cayman. l

Yet for some strange reason, isn't all that much faster or quicker than some cars with half the power/torque :-)

[gk_ghig14]

Originally Posted by jamesqf

Yet for some strange reason, isn't all that much faster or quicker than some cars with half the power/torque :-)

Somebody has never been racing lol
2014 Chevy Corvette Stingray Z51 vs. 2014 Porsche Cayman S Comparison Test on Edmunds.com

4 tenths of a second and 5 mph trap speed difference in drag racing, and 2.4 seconds in road racing is huge!

Oh and last I checked 325 isn't half of 460

[cbaber]

Originally Posted by jamesqf

Yet for some strange reason, isn't all that much faster or quicker than some cars with half the power/torque :-)

It's actually a lot faster, as fast as you would expect with the power difference. 0-60 times are all about power to weight, and it seems to be right on par with the significant differences between the 2 cars. The Cayman and C7 weight about the same, the difference in speed comes from the fact that the Cayman produces 275 hp vs the 425 HP of the C7. 0-60 times are 5.1 for the base Cayman w/PDK, 3.8 for the C7 M/T. If you look at other cars that can do 0-60 in 3.8 seconds, you would find the Ford GT, Ferrari F40, Audi R8, Lambo Gallardo, etc. The C7 is actually extremely fast for the amount of power it produces relative to other options on the market (past and present), like the Porsche 911 Carrera S. And when you factor in the price, it's the best value in sports cars.

So since we are comparing the Cayman vs C7, you get a much faster car (it's speed would cost you $100k if you bought a Porsche that fast) that gets the same fuel economy, for around the same price. Bottom line, whether or not it has an old school engine doesn't really matter, because it gets damn good gas mileage relative to it's performance, no matter what car you compare it to.

Bottom-Bottom line, if the Cayman 2.7 had the same HP numbers and did 0-60 in the same amount of time, it wouldn't get the MPG it gets now. So maybe the big V8 is an advantage here.

[cRiPpLe_rOoStEr]

Originally Posted by serialk11r

I want to like the Corvette but I just can't get over the pushrod V8, whose <7k rev limit is kind of lame.

But the pushrod V8 is exactly why I still like the Corvette.

[niky]

Part of the Corvette's fuel economy can definitely be laid at the door of the pushrod engine.

The two-valve combustion chamber that makes for less flow at high rpm and less hp per liter than other cars makes for better low-rpm running... and with direct injection and higher compression, it gets even better. The new 6.2 has nearly the same torque as the old 7.0.

And the simpler hardware compared to other high-performance engines makes it very compact and light.

Perhaps going forward, it's better to discuss horsepower per pound of motor instead of average horsepower per liter... as the liter part doesn't always translate to lower consumption (at speed) and the peak horsepower part doesn't tell you a whole lot about the engine's performance.

Just imagine, though... if you could get similar benefits in terms of economy out of a small motor built the same way. Say, a Volt range extender made of a V2 cut out of the LT1...

[cRiPpLe_rOoStEr]

Originally Posted by niky

Perhaps going forward, it's better to discuss horsepower per pound of motor instead of average horsepower per liter... as the liter part doesn't always translate to lower consumption (at speed) and the peak horsepower part doesn't tell you a whole lot about the engine's performance.

That's why I really hate the current tax structure based on the displacement of the engines, as usual in Europe, Japan and the Republic of Bananas. Many small engines such as the 1.0L ones actually get worse mileage than a 1.6L, basically because due to the lower taxes the automakers throw the smaller engines into some vehicles that are kinda oversized to them.

Just imagine, though... if you could get similar benefits in terms of economy out of a small motor built the same way. Say, a Volt range extender made of a V2 cut out of the LT1...

I've already considered to adapt a Harley-Davidson V-Twin into a compact car, that would be supposed to work basically the same way

[serialk11r]

Originally Posted by cbaber

So since we are comparing the Cayman vs C7, you get a much faster car (it's speed would cost you $100k if you bought a Porsche that fast) that gets the same fuel economy, for around the same price. Bottom line, whether or not it has an old school engine doesn't really matter, because it gets damn good gas mileage relative to it's performance, no matter what car you compare it to.

Except the fuel economy isn't the same. I guess we should be talking about the Cayman S, with its 3.4L engine, to make things slightly more fair, but it's rated higher on the EPA than the Corvette.

But yes the fuel economy is surprisingly good on the Vette, but I wouldn't want to be caught in stop and go traffic with that 6.2L V8 :P Even in 4 cylinder mode I imagine that thing drinks more than its fair share of gasoline while idling.

[UltArc]

Originally Posted by serialk11r

Except the fuel economy isn't the same. I guess we should be talking about the Cayman S, with its 3.4L engine, to make things slightly more fair, but it's rated higher on the EPA than the Corvette.

But yes the fuel economy is surprisingly good on the Vette, but I wouldn't want to be caught in stop and go traffic with that 6.2L V8 :P Even in 4 cylinder mode I imagine that thing drinks more than its fair share of gasoline while idling.

Start stop will be coming- and they want eventual hybrid power trains. GM is on a good track, though many purists will surely be upset.