30+ MPG With V8, Rear Drive?

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I'm surprised that the OP can't get better MPG's than that out of his Merc. My Merc had 2.73 rear gears and would get outstanding MPG's on the highway. City was another story.
 
If you drive a V8 car with a light foot it can get pretty amazing gas mileage, but it's not as forgiving when you drive it hard! With my Corvette it's got enough torque that even with a light foot on the gas you can pull away from a stoplight at the same pace as (or faster than) everyone else without even going above 1500rpm. So if I drive it like that and keep it at the speed limit on the highway, I can easily average 23-24 in mixed driving, and as high as 32.5 on a pure highway run. Although in my case that great mileage is offset a lot by the need for premium fuel.
 
Originally Posted By: austinlunsford
...but when I filled it up when I got back I kept putting more fuel in because I was like there is NO way that I went that far on 10 gallons, so in all honesty, I probably got even better fuel mileage than I said I did lol.


I worked "out of town" yesterday. Filled up on the way out. Filled back up on the way back in. Same gas station. Different pump.

After 106 miles, I could only squeeze in 3.1 gallons. I don't want to go overflowing it, wasting my gas money on the ground and working out my purge system so I quit after a couple of clicks.
34mpg????!!!!! No freakin' way. Not on E10. I only got 31mpg on rural Oklahoma E0.
It's gotta' be the gas pump.
 
Kudos! Those mid 90's T-Bird's are great cars! Those 4.6L are already rated at a decent mid 20's so getting in the very low 30's on a long highway trip shouldn't be insanely hard to pull off. Either way not too many here can boast 30mpg from a V8.
 
Originally Posted By: dwcopple
I'm surprised that the OP can't get better MPG's than that out of his Merc. My Merc had 2.73 rear gears and would get outstanding MPG's on the highway. City was another story.

nope, i cannot. the best i ever have with the land yacht is 27.8 mpg. it weighs around 200 more pounds than the TBird, and it kicks down into 3rd gear too much on the highway, whereas my thunderbird will never leave overdrive. TBird also has electric fan rather than the merc with its mechanical fan, and I've heard that cause more drag on an engine, resulting in less mpgs. i don't know the extent of the truth on that though
 
Originally Posted By: Patman
If you drive a V8 car with a light foot it can get pretty amazing gas mileage, but it's not as forgiving when you drive it hard! With my Corvette it's got enough torque that even with a light foot on the gas you can pull away from a stoplight at the same pace as (or faster than) everyone else without even going above 1500rpm. So if I drive it like that and keep it at the speed limit on the highway, I can easily average 23-24 in mixed driving, and as high as 32.5 on a pure highway run. Although in my case that great mileage is offset a lot by the need for premium fuel.

your vette is a 6 speed, right?
 
I get decent MPG (27+ at 80Mph) in the M5. That's a 3900lb sedan with 400HP.

I imagine if I slowed down, turned off "sport" and was light on the pedal, I could get it above 30.
 
Originally Posted By: austinlunsford
Originally Posted By: Patman
If you drive a V8 car with a light foot it can get pretty amazing gas mileage, but it's not as forgiving when you drive it hard! With my Corvette it's got enough torque that even with a light foot on the gas you can pull away from a stoplight at the same pace as (or faster than) everyone else without even going above 1500rpm. So if I drive it like that and keep it at the speed limit on the highway, I can easily average 23-24 in mixed driving, and as high as 32.5 on a pure highway run. Although in my case that great mileage is offset a lot by the need for premium fuel.

your vette is a 6 speed, right?


Nope, mine actually has the worst combination for gas mileage, as it's the automatic with the optional 3.15 rear axle (standard axle is 2.73) It would get probably 2-3 more MPG on the highway with the 6 speed manual, as it would be revving at only 1300rpm at 60mph instead of 1700.
 
I love my 1997 Tbird v8 with sports package, too...155k miles and still going strong
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but i don't get 30+, probably 26-27 mpg hwy
 
My best ever MPG record was done under the same circumstances: window cracked, no AC, thin semi-summer air, 58 MPH or so, long trip with hot oil. 15-20% better than usual.
 
Originally Posted By: Patman
Originally Posted By: austinlunsford
Originally Posted By: Patman
If you drive a V8 car with a light foot it can get pretty amazing gas mileage, but it's not as forgiving when you drive it hard! With my Corvette it's got enough torque that even with a light foot on the gas you can pull away from a stoplight at the same pace as (or faster than) everyone else without even going above 1500rpm. So if I drive it like that and keep it at the speed limit on the highway, I can easily average 23-24 in mixed driving, and as high as 32.5 on a pure highway run. Although in my case that great mileage is offset a lot by the need for premium fuel.

your vette is a 6 speed, right?


Nope, mine actually has the worst combination for gas mileage, as it's the automatic with the optional 3.15 rear axle (standard axle is 2.73) It would get probably 2-3 more MPG on the highway with the 6 speed manual, as it would be revving at only 1300rpm at 60mph instead of 1700.


Yes, the newer C6 Vettes with EITHER the 6 speed Tremec manual, or the 6L80E auto will get even crazier highway gas mileage, especially with the (numerically) lower rear axle ratios!!
It's hard to beat super overdrives combined with great torque, and a super low frontal cd.

There is pretty much NOTHING else on Earth that gets this kind of fuel mileage, combined with this performance, for ANY price right off of the showroom floor.
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Originally Posted By: dailydriver


Yes, the newer C6 Vettes with EITHER the 6 speed Tremec manual, or the 6L80E auto will get even crazier highway gas mileage, especially with the (numerically) lower rear axle ratios!!
It's hard to beat super overdrives combined with great torque, and a super low frontal cd.

There is pretty much NOTHING else on Earth that gets this kind of fuel mileage, combined with this performance, for ANY price right off of the showroom floor.
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It wouldn't surprise me if in 5 years time we see a new Corvette that can get over 40 MPG on the highway, while still running roughly the same quarter mile times as the current models.
 
When the Trans Am was bone stock, it would run 13.10 is in the 1/4 and pull down 30 to 31 mpg in 6th gear going 70 with a 3.42 gear, around town I could see 18 to 19. I can do much worse if I put my foot in it. Even now with heads, cam, exhaust, tune and gears. I can still pull down right around 24 to 25 mph in 6th gear on the highway w/ the cruise on 70.
 
Originally Posted By: Patman
Originally Posted By: austinlunsford
Originally Posted By: Patman
If you drive a V8 car with a light foot it can get pretty amazing gas mileage, but it's not as forgiving when you drive it hard! With my Corvette it's got enough torque that even with a light foot on the gas you can pull away from a stoplight at the same pace as (or faster than) everyone else without even going above 1500rpm. So if I drive it like that and keep it at the speed limit on the highway, I can easily average 23-24 in mixed driving, and as high as 32.5 on a pure highway run. Although in my case that great mileage is offset a lot by the need for premium fuel.

your vette is a 6 speed, right?


Nope, mine actually has the worst combination for gas mileage, as it's the automatic with the optional 3.15 rear axle (standard axle is 2.73) It would get probably 2-3 more MPG on the highway with the 6 speed manual, as it would be revving at only 1300rpm at 60mph instead of 1700.

so is it a 4 or 5 speed AT? I'm amazed my car has a higher gear set than a Corvette! I thought Vettes would have 3.73s or something, but I know your car is a beast on the top end, so you probably need the lower axle for top speed no?
 
Originally Posted By: austinlunsford


so is it a 4 or 5 speed AT? I'm amazed my car has a higher gear set than a Corvette! I thought Vettes would have 3.73s or something, but I know your car is a beast on the top end, so you probably need the lower axle for top speed no?


It's a 4 speed automatic, they never did put a 5 speed auto in the Vettes, they went straight from a 4 speed auto in 2005 to a 6 speed auto from 2006 on.

I'm not sure if they necessarily chose the axle ratio for top speed, I think that they probably went as numerically high as they could without sacrificing too much in the way of MPG.

The new Vettes with the 6 speed auto have even taller rear axle ratios, 2.56 with an option for 2.73.
 
Our full size '04 Jaguar has got 30+ mpg at normal highway speeds from the first day my wife drove it off the lot seven years ago, and has always got low to mid 20's around town.

It's our economy car, and it probably is not even really broken in yet; the odometer was at 28,142 this morning when I parked here at the office.

Small V8, all aluminum construction, 6 speed auto = good fuel mileage, and I'll bet with a good reaction time I could put it in the high 13's in the quarter.
 
Originally Posted By: Patman


It wouldn't surprise me if in 5 years time we see a new Corvette that can get over 40 MPG on the highway, while still running roughly the same quarter mile times as the current models.


I hope you're right Patman, but I'm not optimistic.

Our Xj8 has the benefit of all the high tech goodies save DI, is made wholly out of lightweight aluminum, has a six speed (don't know the rear axle ratio), and it has no chance of meeting the new fuel economy mandates.

I don't see big V8 sedans as being around much longer, at least not at prices the average joe can drop on a car.
 
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