i have a 07 f150 getting 17 mpg in town, i would like to get 20 MPG in town, this is a 5 speed, i do not shift into 5th gear. max in town in 40 MPH. i have 3.55 i was wondering would 3.27 getting me to that 20 MPG?

 

17 mpg is a good number for a pickup, and shifting into 5th will probably help your numbers.
As far as the gear change goes, have you priced it out yet? last I knew it was $1500++
That is a lot of fuel.how many miles are you going to have to drive before you actually start saving $?

 

not yet, i have tried 5th in town and it ust bogs the eninge down

 

After I asked you those questions I ran some numbers.

I figured 15,000 miles in a year. And currently 87 octane down the street is $3.87

15,000 miles/ 17 mpg = 882 gallons annually for a grand total of $3413.34
Now 15,000 miles/ 20 mpg = 750 gallons annually for a grand total of $2902.50

That will end up being a savings of $510, so you will not see any savings for about 3 years if my price on a gear change and estimated miles per year are accurate

 

still ot bad, i hav this truck on paymens for the next 4 years and that ins and extra few bucks i can throw at payments to get it paid off faster. Now next quetions can i get a set of 3.23 for my axle?

 

That part I'm not sure about. Everyone else I have seen went with taller gears r to accommodate bigger tires. Also I didn't see if your truck is 4x4 but if it is you will need to change both sets of gears

 

ok i did some reserach i can get a set of 3.31 for just undr 500 bucks (oem)
\or i can get aftermarket high perf 3.31 for just over 300
Aftermartket 3.31 High performance Yukon Ring & Pinion gear set for Ford 9.75" in a 3.31 ratio - YG F9.75-331

oh it is a 2wd so i only have to change one set, going to call on mondya and see what install would cost

 

Good luck, maybe someone else can do the math for potential mpg gains with that gear set.

 

Lets hope so. A question is free and non commital

 

the 3.31 gear set would drop my RPM by 150, not worht the 600 bucks to do the job

 

Do they make smaller gears for your Axel? Or you could get skinnier tires to help the mpg

 

smaller????? the owest numercaly i can get is 3.08 and i think i cna go max of 3.73

 

Wouldn't shifting into 5th basically do the same thing, all either will do is lower the rpm's

 

5th gear makes my ening bog intown,and i know that is bad for milage as well. For th skinnier talller tire what would be a good size. I would like to stay with a 17 inch max. If there is a way of going to a 16 inch tire that would be great.

 

[QUOTE=SCRWDRVR;11864625]Wouldn't shifting into 5th basically do the same thing, all either will do is lower the rpm's[/QUOTE What he said changing gears or taller tires are going to do the same thing as shifting to 5th. You are probably at your Max MPG.