Guys I installed a leveling kit ( full front springs and blocks in rear) so I raised my truck roughly 2.5 inches. I had a mishap and when I took my truck to the tire shop they showed me where I had some seperation in the tires I was running and highly recommended getting new tires. I was expecting to do so this spring because of the leveling kit anyways. I wanted the largest tires I could fit which the leveling kit manufacture said 33x12.5x16 was the recommended tire size. My rims are not that wide but I put on 295x whatever x16 Nitto Grapplers and I like to look and hope thay are big enough, it was the biggest they had other than 35 inch tires and I thought they would rub, And I had to do something right then because the other tires were toast. So my question is with the 295,s and stock 3:73 gearing will my speed be way off on the speedometer? Thanks guys.
Clint.

 

at 70 mph expect the speedo to be showing 5mph low, or very close to that. If you want to drive 50, make it show 47, if you want to drive 65, make it show 60.

 

great question. i just got a set of 18'' wheels off a 08 f250 w/ 275/70/18 will these even fit on my 03 ex, and will this change my speedo, or hurt the trans

 

Tire size is the only thing that will change the speedo. You can have 35's with 16 inch wheels, or 20 inch wheels and it will read the same.

 

One thing that I noticed on my '01 was every time I would drive by one of those radar signs my speedo would read lower than the sign with the stock 265/75/16 tires. My second set were 305/70/16 and then 295/75/16 since which are both basically 33" tires. My speedo is right on the money now.
Others have said they've noticed the same, so you might want to check it out.

just my experience on my '01

Austin

 

Mines not even close......... GPS says 77, speedo says 65.

 

Wow, that is a big difference. Just goes to show how much a 5" increase over the stock 265/75/16 can make.

Mine is dead on until 75 mph speedo then its 78 mph actual mph at 2" over the stock 265's it came with.

I wonder if some speedos are calibrated for the standard 30" 235/75/16 tires?
That really would make a big difference.

Thanks for the info.

Austin

 

Online tire size speedo calculator:


http://www.onlineconversion.com/bigger_tires.htm

 

Gps is good for more than just directions!

android has an app for that, too... http://appcrawlr.com/android-apps/be...s-ground-speed https://play.google.com/store/apps/d...speedview.free

 

Az bringing back an oldie but a goodie.

 

I'm running 38's with factory gearing & my spedo was almost 10 miles off from what my GPS said. I was able to adjust the spedo though with my AE & it is right on the money now. That AE is a wonderfull thing! :0)

 

With the proper reader, u can go in and change the revs/mile and get your truck showing the correct speed again. More importantly, it will restore the shift points to the proper places if you are having it lug sometimes. I did it to mine and just went up two sizes over stock.