Fuel milage

[87MonteSS]

A 2.41 rear with a 4 speed OD trans? Are you sure about that? If that is the case you're killing fuel mileage because the engine won't ever be into the power band that will get good mileage. What RPM is it running at 60MPH?

I get about 18 in the city and 24-25 on the highway with the basically stock L69, 200-4R and 3.73 gearing.

 

[Chevyman85]

yea i would guess about 10 for me also. 10 gallons to the mile that is :lol: . but hey got to do what i can to eat up some of that gas those japanese cars are leaving behind.

That does seem a little on the low side. Hows the Monte running? You should be getting better mileage with stock gears and a 4spd. Check your timing and carb!

 

[FULL_MONTIE]

no the thing runs great. and after looking at it closer today it appears that my gauge may be a bit off. is seems to float around a bit. it gives me a close ball park, but exactly what i have in my tank is a mystery. in all seriousness id guess between 10 and 15 mpg. and i know that the people who had it before me didn't mess with it because they never even bothered to change anything but the oil on the car. it was essentially on slicks when i found it.

 

[pontiacgp]

A 2.41 rear with a 4 speed OD trans? Are you sure about that?

that's the gear ratio (GU1) listed on the label in the trunk

 

[RedHotRegal]

are you quoting l/kph or g/mph? My regal got great milage on the highway with that gearing but but sucked in the city. I get better city milage now with 3:42 in the rear but less on the high way. I found the engine was lugging in every gear in the city.

 

[FULL_MONTIE]

g/mph. it could be because i am mostly going through city driving.

 

[srercrcr]

I also am very curious about what rpm you turn at 60 mph.
Does anybody know what the 4th gear ratio is in this auto OD transmission?

 

[87MonteSS]

I also am very curious about what rpm you turn at 60 mph.
Does anybody know what the 4th gear ratio is in this auto OD transmission?

OD is 0.67:1

Final drive in that GP would be 1.62:1

My Monte SS with the 3.73 rear has a final drive of 2.50:1 which brings me to 2300 RPM @ 60MPH

Assuming the same tire size, the GP would be at 1490 RPM @ 60MPH.

This doesn't seem right, never mind good.

 

[srercrcr]

Thanks for the info. I have a Ford six pickup I ordered years ago with a 3.08 and 4 spd manual OD of .70 = 2.15....it turns 1600 rpm at 60, gets 20 mpg highway...awesome considering its a Super Cab and a 8 ft bed.
With a manual transmission I can shift at will (3rd is 1:1), but an automatic seems like it wouldn't like the unusual gearing, unless you shift it by hand all the time, which defeats the purpose of being an automatic.

 

[Chevyman85]

Thanks for the info. I have a Ford six pickup I ordered years ago with a 3.08 and 4 spd manual OD of .70 = 2.15....it turns 1600 rpm at 60, gets 20 mpg highway...awesome considering its a Super Cab and a 8 ft bed.
With a manual transmission I can shift at will (3rd is 1:1), but an automatic seems like it wouldn't like the unusual gearing, unless you shift it by hand all the time, which defeats the purpose of being an automatic.

What kind of for do you have with 3.08:1 Gearing? Thats a strange factory number. Is it a Ranger?