quote:I so about the same with my 96 Corvette. Just right about 27 mpg on a trip. The seats are comfortable enough and the stability good enough that it's very comfortable to drive on a long trip. The seats and stability make up for the firm ride in comfort. So far my longest distance in a day is just over 600 miles, which was easy.
Originally posted by Patman: I found my 98 Corvette to be a great road trip car. I've only taken one road trip so far, a 350 mile trip to Michigan but it was very comfortable for the 5 hour journey, and got 27.5 MPG too.
quote:Why limit yourself to 5th gear On my 96 Corvette LT4 6 speed, the engine only turns about 1600 rpm at 70 in 6th, which is a 0.49:1 overdrive! It's strictly an economy cruise gear. Gearing makes a big difference in economy if your engine has broad power range and can pull the gearing. I run right about 27 mpg on a long highway trip at about 70 mph. I have to go to take me directly to jail speeds, or run in too low a gear to get below 25 mpg on a long highway trip. On my last highway trip I tried running in 5th (0.74:1) a couple of times at 70 mph and about 2400 rpm and mentally averaging the instantaneous mpg readouts. 5th looks like it gives about 3 to 4 mpg less than 6th under those conditions. I'm not a GM fanboy, but GM has done a very good job at getting fuel efficiency out of some of their engines. At 1600 rpm, friction loses are lower, and the engine is only trying to pump 2/3 as much air. As long as they can tune it to run right at those speeds, the engine is acting like it's only 2/3 as big in 6th as in 5th. It also helps that Corvette is relatively light car at 3200 lb, has a small frontal area and low coefficient of drag. Those economy features are partly off set by the steam roller width tires .
Originally posted by moribundman: I find it the gas mileage some of you guys get out of relatively large engines amazing. While my old VW Scirocco (1.8l 95 hp) got about 33 mpg, my Chevy (2.8 V6) and Buick (3.0 V6) got maybe 20 mpg. And my Audi (2.8 174 hp V6) rarely exceeds 28 mpg. Do you all coast in 5th gear at 40 mph or what?
quote:My 87 Volvo 740 Wagon with a Turbo 2.3 liter runs at 2450 rpms at 70 mph in 5th. It weighs in around 3150 lbs. At 3000 rpms she is cruising between 86 - 87 mph.
Originally posted by moribundman: XS650, 1600RPM in 6th gear at 70? In a sportscar? My A4 Quattro weighs in at 3228 lbs (1465 kg), so it's actually heavier than your Vette. At 70 I'm at around 3k RPM in 5th, Sorry, no 6th gear. Top speed is electronically limited to 130 mph. The CW air resistance coefficient is about 0.28.
quote:A 0.49:1 overdrive ratio will do that . It's strictly an economy cruise gear. The first 5 ratios make for a good performance transmission. 5th is just right for the 165 mph (actual) top speed. It's a ragtop, the coupes are faster. Not bad for a stock 9 year old Chevy.
Originally posted by moribundman: XS650, 1600RPM in 6th gear at 70? In a sportscar?