grishw1

Love my truck, but am getting 11.5 to 12.5 per gallon. I drive between 25-30K per year. What do you guys think the cost would be to switch out gears to the 4.10's? Would that give me a few more miles to the gallon and pay for itself in a short amount of time? Any thoughts or experience appreciated.

12GBMPlatinum

Here's some math to help you figure it out:

Given 12.5 MPG on 3.55 Gears @ $3.35/Gallon = 26.8 Cents Per Mile
Cost To Drive 25k Miles/Year = $6,700/Year

Assume 14.5 MPG on 4.10 Gears @ $3.35/Gallon = 23.1 Cents Per Mile
Cost To Drive 25k Miles/Year = $5,775/Year

Difference is $925/Year

Cost For 4.10 Gears = About $700
Labor = $0 to, realistically, $700 to $1000

In the first year if you did it yourself you'd save $225. If you have someone else do the install you're looking at a true cost of between $475 to $775.

Savings from second year on would be about $925 per year.

If you need it for performance that's one thing. If you are chasing MPGs you really need to consider how much it is worth it with respect to how long you'll keep the truck, etc.

BTW, I went with your hypothetical mileage savings as I really have no idea how much you would gain by doing the swap.

grishw1

Good stuff, thanks! I think for sure it will pay for itself. I will have the truck 2.5-3 years. The 3.55 is fine performance wise I just hoped I would get 13-14 mpg's.

Nospleen

Did you correct your speedo? It may not be as bad as you think...

grishw1

In the process of doing that now. I am a tenth of a mile off per mile. will add that when I fill up again.

TexasEd

So that means every 100 miles on your odometer is really 110 miles of road traveled. Your 11.5-12.5 MPG is really per 0.9 miles to correct for it

11.5/.9 = 12.77
12.5/.9= 13.88

To correct your calculations add the 10% on to the miles before you divide the number of gallons.

(Miles *1.1)/Gallons = true MPG

bodam

Won't switching to 4.10's raise your highway cruising RPMs?


Wouldn't that effect your highway mileage for the worse?

Wanted33

^^^^^Yeah, that's what I was thinking. The equation I'm seeing is: Lower gears + Higher RPM's = Less MPG's.

NASSTY

You will probably gain a little in city MPGs but lose a little in highway MPGs.

zimmer0

iTrader: (1)

technically yes but with 6th gear it wouldnt be affected too much IMO. It will potentially save your transmission and rear end by gearing it.