Questions about gearing on the superduty - Diesel Forum

AzSD · 03-03-2002, 04:42 AM

Im getting ready to order a new superduty and have been looking at this site and others and fuel mileage, power, and some other questions end up with the gear ratios getting brought up. But it seems most are talking about the auto tranny. I am wanting the 6 speed for what I do(working I tow heavy loads everyday). My question is with a V10 should I still get the 4.30s or would 3.73s be better since the 6 speed starts out so much lower with the O/D being very close on both the 4 speed and 6 speed. It will probably be stock for awhile, but ill eventually cave in and go up to 35" tires down the road. What are your suggestions? How does the fuel mileage compare with the manual vs auto tranny?

The Archer · 03-03-2002, 07:43 AM

If you are going to get 35 inch tires then get the 4.30's. If you get the 3.73's and put 10,000 lbs behind you you will never stay in overdrive with 35's.

I would speculate that you will get unloaded fuel mileage between 10 and 14 depending on driving style. You can expect a 10% increase if you get the hand shaker.

dan4x4 · 03-03-2002, 03:32 PM

If I didn't do so much stop and go city driving, I would have the 6 speed. I had the 3.73 in my last SD, now I have the 4.30 and I am much happier.

I would still have the 4.30 if I had gone with the 6 speed.

I get 12-13 mpg on the highway with my truck (auto tranny). I imagine the 4.30 and 6 speed would generate a touch higher mpg numbers.

Overall mpg will always depend upon how you drive and how heavy you tow.

I would get the 4.30 gear. This covers your loss of gear when you put larger tires on.

Dan

Stan Wright · 03-04-2002, 04:00 PM

I'd say get the 4.30's since you're considering larger tires.

redone · 03-04-2002, 10:39 PM

I have the 4.30s with an auto. I'd go that way again. Great for towing, plus I have 295 BFGs, so 3.73 wouldn't be the way to go. I just had a US Gear OD installed last week, so now the ratios are actually 3.44 and 4.30.

Engineered Madness · 03-06-2002, 09:48 AM

Redone, Do tell more on this US gear OD. I've just looked at their web site and i'm very impressed. I bought my truck "just because", i dont pull, its a daily driver and used for road trips. Im looking to increase the fuel mileage and i'm thinking this unit will help. If you could fill us in on the details of the install and operation that would be great. Thanks.

SUPERDUTYAZ · 03-20-2002, 11:34 PM

Hey if your in PHX personal e-mail me,Mark