Speedo and 35's
Thread Starter
|
Mountain Pass
Joined: Nov 2003
Posts: 157
Likes: 1
Speedo and 35's
I changed me stock tires to 35's and was wondering what the difference in the mileage and speedometer be. I have noticed that I don't get the mileage I used to and was thinking that I need to recal the speedo and odometer. What is the difference.
Senior User
Joined: Mar 2007
Posts: 348
Likes: 0
Originally Posted by cclgeo
I changed me stock tires to 35's and was wondering what the difference in the mileage and speedometer be. I have noticed that I don't get the mileage I used to and was thinking that I need to recal the speedo and odometer. What is the difference.
I do know that a lot of the re-programmers/tuners for the on board computer advertise being able to enter all of the specs for the drive train, including tire diameter, to ensure proper PCM info.
If the PCM also drives the speedometer gauge then I would think this might help.
Thread Starter
|
Mountain Pass
Joined: Nov 2003
Posts: 157
Likes: 1
Now when I figure out my MPG, if the tires are bigger and my odometer is off, it will give me a false reading. Since the tires are bigger won't that make the speedo say I'm going slower that I am really going, and in turn show that I have not gone the correct distance on the odometer giving me a false MPG????? The reason I ask this is I used to get about 10 to 11 MPG, so if I filled up 10 gallons I should be able to go 100 mile about. Now if I fill up 10 gallons it will say that I went about 75 miles. That is some really crappy gas mileage. But if the new tires make me have to add a % correction then I should still be getting around the same mileage.
Last edited by cclgeo; Apr 12, 2007 at 07:24 PM.
Laughing Gas
Joined: Jan 2004
Posts: 1,142
Likes: 2
From: Denver, CO
I have 35s on my F250 with 4.30s. My odo. is off .1 every mile. That is running from mile marker to mile marker. When the speedo is showing 65mph Im actually doing 72mph.
On my last trip from Colorado to California and back I set the cruise at 70mph which was 2500 RPM and I averaged 12.25mpg. Every 100 miles I added 10 miles to get my correct average mileage.
On my last trip from Colorado to California and back I set the cruise at 70mph which was 2500 RPM and I averaged 12.25mpg. Every 100 miles I added 10 miles to get my correct average mileage.
