Tire Size/Odometer/Speedo Correction...

54warrior · 05-08-2007, 05:56 AM

I see this being asked alot, so I thought I'd make a post that describes why changing to a larger size of tire also changes your speedometer and odometer readings. It also explains how to determine the "correction factor" which can be used to calculate how many miles you really did travel, or how fast you are really going.

I also showed the correct method for determining the circumference of a metric sized tire (ex. 245/75/17).

Maybe this could be made a sticky if you think it's helpful??

import2nr · 05-08-2007, 07:18 AM

i dont have larger tires on my truck YET.. but is there someplace we can take our trucks to to have the speedomoter recalibrated for the larger tires?

**Nissan Mike** · 05-08-2007, 07:47 AM

Thanks for explaining this in detail,this might make the math a little easier
http://www.miata.net/garage/tirecalc.html

54warrior · 05-08-2007, 07:51 AM

Quote:

Originally Posted by import2nr

i dont have larger tires on my truck YET.. but is there someplace we can take our trucks to to have the speedomoter recalibrated for the larger tires?

I am unaware of any such programmer/calibration tool.

**Blackbeauty** · 05-08-2007, 07:55 AM

I would think the dealers can do it. I had them recalibrate my Ford when I upsized the tires. It's just an adjustment to the computer. They just used a sequence of on/off with the ignition switch and the odometer set button. I cannot believe it's not built into the ECU programmability. If so, this is a MAJOR screw-up by Nissan!

Rick Guess · 05-20-2007, 09:25 AM

cool... i will use this when i get my new tires

Armada · 06-06-2007, 12:15 PM

If the dealer can't do it, just get a cheap GPS. It doesn't even need to have navigation features. That will give you true road speed, and distance travelled, etc. regardless of tire size and will allow you to switch tires back and forth without any recalibration.

That's what I do on my old CJ5 Jeep with 36 inch Super Swampers when I play in the mud and 31 inch AT's if I'm going to be on the street. The GPS doesn't care.

*TitanTailGator* · 08-23-2007, 07:28 AM

Any new info on speedo/odo recalibration tools for the Titan? Been searching the net and can't find anything....

wrecks8 · 10-24-2007, 04:32 AM

a thought here...

can the owners with the NAV system make the asjustment? i know there are a lot of things that interface can do.

also, what about the tire pressure sensors? obviously, dif size tires have dif tire pressures..?? and do they work with aftermarket wheels?

wrecks

Demondw3 · 10-24-2007, 05:18 AM

With 35" tires your speed is of by 5mph. I have tested this theory with my GPS and Highway patrol. Highway turned out to be a more expensive test.

detroitfan7 · 12-06-2007, 09:33 AM

Hi, I am new here, but I was wondering if anyone could tell me if there is an alternative tire size for a 05' LE model besides the 265-70R-18. I am having trouble locating tires locally here that will fit for what I want to do with the truck.

thanks

07KC4x4 · 12-06-2007, 06:26 PM

Oddly enough and I really don't get it, but my speedo isn't off by like any. figured this out when the cops set up one of those speed check things where it tells you how fast ur going, and it was right on...weird considering i went to 35's

**bills1974** · 01-03-2008, 05:43 AM

Quote:

Originally Posted by 07KC4x4

Oddly enough and I really don't get it, but my speedo isn't off by like any. figured this out when the cops set up one of those speed check things where it tells you how fast ur going, and it was right on...weird considering i went to 35's

Same here, I assumed I'd be off by about 5mph, but my speedometer is right in line with my GPS...Unless my GPS is off.

J-rod03 · 01-16-2008, 08:02 PM

I have an 08 se Titan and recently went with a 6" lift and 35's and my speedo is off about 4-5 mph. I went to my local dealer to see if they could recalibrate my ecu, and the computer wouldn't show a option for recalibrating the speedo! I went with the 2* advance, if anyone has been successful with this please let me know. I my have been because mine is a 08 , it seems like nothing else works the same on the earlier models as the 07-08's so nothing surprises me.

TitanTech659 · 01-22-2008, 09:53 PM

It is not possible to recalibrate the speedo on the Titan. Also you can use the tire pressure sensors on some but not all aftermarket wheels. It depends on the hole that the valve stem goes in. It doesn't matter what the psi rating is on the tires as long as all the tires are set to the same pressures.