MPG with the LT-1

[Stallion]

Just curious, but how many miles do you get per gallon off of the LT1? Consider that you are an average driver (not bad, not good).

Thanks! :D

TR

[warren s]

One the highway between speeds of 50 and 80 I get about 26 MPG.

[Billy]

When I'm out driving my LT-1 I absolutely don't care at all about the gas milage...actually the more gas I use the more FUN I'm having. You can't put a price on the thrill of driving one. However, for reference, my LT-1 probably gets about 10 MPG average street driving. On the freeways it gets about 15 MPG cruising at 70 MPH, which is about 3500 RPM with the 3.70 gears I have. Hope this helps..........

[Stallion]

warren: >> 26 MPG <<

Billy: >> 10 MPG << >> 15 MPG <<

Why is this? Why are these numbers so different?

Thanks, fellas! :D

TR

[warren s]

A 72 LT-1 is a differnt animal than a 95 LT-1, at 70 mph on the highway my engine is at less than 2000RPM in overdrive, I have a 3.07 rear, still good enogh for a 13.4 et

[Stallion]

Okay, thanks for the explanations! :D

TR

[Billy]

There is no real fair way to compare gas mileage between a vintage LT-1 and C4 LT1. My '72 LT-1 does consume a lot of gas:cool. My '96 LT4 gets great gas mileage (almost 30 MPG at freeway speeds). I love the efficency and power of the LT4, but the LT-1 is still more fun to drive.

[Stallion]

I see what you mean. How many miles, do you know, does the average C3 Vette get?

Thanks! :D

TR

[Billy]

Stallion,

Average would be easy to define with the C4s. With the exception of the '84 Crossfire (at about 210 HP), the LT4 (at advertized ((and under rated 330 HP))) and the ZR1, the "average" C4 made from 225-240 HP. It is much more difficult to quantify "average" among the C3. On one end of the scale you have the high-horse early '70s LT-1 and big blocks and on the other end is the mid-late L-48 with only around 170HP. Any Corvette has the right building block :L for horsepower. All of the factory advertized horsepower ratings are readily available for comparison on the internet. Also keep in mind that the torque developed by a motor can make a significant difference in how a car feels when driving. My '82 always felt faster off the line (and actually quicker until about 30 MPH) than my friend's L-98. Because he had a good 25-30 more HP he could easily beat me after a while, but in any event a good torque curve makes for a pleasurable street car.

[Stallion]

So the '82 probably had more Torque than his L98?

TR

[Billy]

I don't have the figures in front of me, but I believe the Crossfire does have a little more low range torque than the TunedPort

[Evolution1980]

:L If you are concerned about gas mileage, you shouldn't be driving a vette... :L

[Stallion]

:D I'm not really concerned at all. Just curious. Thanks again! :)

TR

[Robert N]

For LT-1 mileage, you will have to go year by year on the C3s. The 1970 LT-1 is a wildly different animal than the 72 LT-1.

I have gotten as little as 6 and as much as 15 mpg. Usually I sit around 9-10.

[Stallion]

Have you ever considered putting fuel injection into your Vette, JRZYDVL? There's a thread I started on this topic and your mileage made me think. :D

TR

[Robert N]

Since mine currently has few matching parts under the hood and will not be an NCRS car, that thought occurred to me. I would lean more for better driveability (cold weather starts, etc) than for mpg.

I do like the feel of a carbed car when you get on it.

[Billy]

JRZDYVL,

I've never driven a '70 LT-1, but I don't know that I'd consider it "wildly" different from the '72. My '72 LT-1 is all stock (as far as I can tell) and it screams. I realize the compression was less in '72, but that also changes torque curve characteristics. Also don't forget the numbers game corporate GM was playing in the early 70's. It is certainly not as fast as my '96 LT-4, but still an awesome car....


by the way..where in AZ? I live in Tempe.

[Robert N]

Tucson.

The compression was dropped from 11:1 to 9:1 as you mentioned and the torque characteristics.

The 70 and 72 both hit peak torque @ 4000 RPM, but the 70 is 380 and the 72 is 280.

The 72 hp is 255 NET and the 70 is 370 GROSS. Assuming a 20% loss when calculating NET from GROSS hp, that leaves the 70 at 296 NET. Based on ET's and track time slips I have seen, the GROSS hp could be as high as 325.

The 70 LT-1 is comparable in power to a base C5 vette.

[Stallion]

Originally posted by JRZYDVL
Since mine currently has few matching parts under the hood and will not be an NCRS car, that thought occurred to me. I would lean more for better driveability (cold weather starts, etc) than for mpg.

I do like the feel of a carbed car when you get on it.

What do you mean? What does a carb feel like? I thought injection was more power. :confused

[Robert N]

There is more power through a fuel injector. Never said the carbed engine was better, faster, or more efficient. The 'feel' is difficult to describe. I personally like the inconsistencies that come from carbs; the fact that you can feel differences as altitude changes, that you can tell when the secondaries kick in, the challenges in tuning a carb for proper air/fuel mixture.

[Stallion]

I definitely see what you mean. As of now, when I get my own C3 I don't think I would put injection in right away. Maybe with time and experience. But, it soudns like carbs might be somewhat of a pain in cold weather. :D

TR

[Robert N]

'somewhat of a pain in cold weather'

is an understatement. While it generally gets only to 40 degrees, if the carb is not perfectly tuned or other things are out of wack, cold starts are no fun. Part of the joy though.

[Stallion]

When you say that the carb isn't "tuned" what do you mean by that? Maybe that the fuel:air ration is off?

TR

[Robert N]

Yes