mpg?

[neatofrito1618]

my mom always bitches about me getting a muscle car cuz of the gas milage. so what do u think a 1970 cutlass with a rebuilt 350 rocket with a intake and exhaust would get in the mpg?

[MagicRat]

12-18 mpg.

It also depends on the tuning, too.
The can run well, but still waste gas if the carb is too rich or the timing is retarded.
Learn how to tune it and how to play with the jetting, timing and advance curve for maximum mileage.

City driving really sucks down the gas for these cars, especially when its stop and go. But highway driving is quite efficient.

[wilwith1l]

Another important thing is rear end. If you get a 4.10 or 4.11 it'll really suck on the highway. On the other hand, a 3.07 will get you better highway mpg. At the cost of acceleration.

[Mines69Olds]

Originally Posted by wilwith1l

Another important thing is rear end. If you get a 4.10 or 4.11 it'll really suck on the highway. On the other hand, a 3.07 will get you better highway mpg. At the cost of acceleration.

Exactly, I have a 1969 Cutlass that had a 350 rebuilt with a 750 double pumper holly and mild cam and headers with 4.11 rear end. Wow that thing sucked the gas like a big block. I'm talking 6 - 8 mpg on a good day.

[Tomsriv]

It depends on the compression ratio too. Higher compression engines get better mileage, but require higher octane. I had a 70 El Camino with a low compression 350 and a stock cam. With headers and a quadrajet I got 13mpg.

[neatofrito1618]

Originally Posted by Tomsriv

It depends on the compression ratio too. Higher compression engines get better mileage, but require higher octane. I had a 70 El Camino with a low compression 350 and a stock cam. With headers and a quadrajet I got 13mpg.

were u drivin normal or were u goin light on the gas and tryin to see how high u could get the mpg.

[neatofrito1618]

Originally Posted by wilwith1l

Another important thing is rear end. If you get a 4.10 or 4.11 it'll really suck on the highway. On the other hand, a 3.07 will get you better highway mpg. At the cost of acceleration.

would a 4.11 give u better city driving mpg.

[Mines69Olds]

No way. The drive shaft would spin 4.11 times for every 1 time that the tires spin. So the engine is working just as hard. So it would build RPM's quicker, using more gas. The whole point of higher gears is to "let's say" use the same amount of power from the engine to spin the tires less.

[neatofrito1618]

thats what i thought. why do they make 4.11's and 4.10's?

[Mines69Olds]

They make them for people who want their cars to be quick. Street racers, quarter mile machine and what not.

[neatofrito1618]

i know how gears work and why people have them but my question was why do they have 4.10's AND 4.11's if there is only a .01 difference.

[NOVA71]

I guess it really comes down to what you want. A muscle car or good gas milage. The two don't really go hand in hand anymore

[Mines69Olds]

With gas prices being like they are most people would rather have lower gears.

[AlmostStock]

Originally Posted by neatofrito1618

i know how gears work and why people have them but my question was why do they have 4.10's AND 4.11's if there is only a .01 difference.

4.10 AND 4.11 would not be available for the same rear axle unit. Only one or the other depending on the make and model of the axle in question.

[AlmostStock]

Originally Posted by Mines69Olds

With gas prices being like they are most people would rather have lower gears.

Lower gears have a higher number and would give you worse gas mileage.
Lower gears = higher number. Higher gears = lower number.