If you have an extended cab F150 (97-03 body style) can you tell me how much of a difference it put in your gas mileage after you got the tires on there?

 

I've got 33's on mine, but I also have 4.56 gears and custom tuning. I get any where from 13 - 16 mpg but that is with mostly city driving and towing a small boat.

 

The big tires are going to kill both gas mileage and performance. You will need to regear and get a tune to get most of it back.

 

i have the 4.2 in my 98 and im running 33"s and i have no power issues and if i drive conservatively i can get 15 with stock tune and gears

 

Im on 33's and my quarter mile time changed less than a tenth of a second. Im running 87 performance tune, and 3.55 LS. I get 14 MPG

 

Really!?

Tires size has a big effect on a vehicle's performance... Especially a V6. I would have expected a larger margin in your track times.

Where they run the same day? Same track conditions? Same temp/humidity ect.?

 

My tire size barely changed about one inch taller. Different day, track was hotter, air was hotter. I was running a 93 tune though, which i just thought of. V6 is not completely powerless. Plus the larger tires made me catch a lot better traction.

 

I don;t see how you guys are getting such good mileage???

I get around 10mpg on each of my whips..Red one on 35's
.. Tan one on 35's

 

Well with 33"s I am 2 inches shorter on the tires and that's alot of extra weight that the truck is pushing around. I went from 16.5 to about 14.8 from 31 to 33 and that's mostly highway stayig around 68-70 crusing and no hard take offs in the city.

It's alot about how you drive

 

^^^Nice truck,

Wish I had that kind of mileage....
Actually, My tan one with a 5speed does better and has bigger tires. 325/65/18. I can pull around 300 to a tank If i watch it.

The red one sometimes doesn't get over 225 a tank...v6auto.

 

I barely ever get over 1800 RPM's unless on the interstate or i want to hear my exhaust. Try some gas saving mods, E-fans, CAI, Exhaust and so on.

 

Did you get your speedometer re-calibrated after you increased your tire size? If not, you do realize that you are traveling more miles then your odometer is reading, thus throwing mileage calculations off.

 

good point my 14.8 average is without a recalibration and im about 7-12 mph faster at highway speeds so i cant imagine how bad it is with 35"s

 

Daayum. I filled up about two weeks ago. My truck has a 25 gallon tank, and I went a little more than 240 miles and was almost at a half a tank. If you do the math roughly its about 19mpg. Since then my truck is in between half and a quarter tank with exactly 313 miles on that tank. Dont ask my how I am getting that mileage, but I will be the last to complain. Only difference is that I have a 4.6.

 

Can't believe how many people estimate gas mileage by how many miles they get on a tank !
You fill up, reset odometer, run untill about empty, refill, get the gallons off gas pump, divide them into the miles, thats the only way to determine MPG. Do this every time you refill,keep a log and average all those and get the most accurate MPG.