2nd Gen Non-Engine/Transmission speed VS tire size?

[johncameron]

My truck's door pannel says the tire size is 246/75/16. I'm running 265/75/16 tires. Does that mean that I'm actually going 4. 7% faster than my speedo says? If so, I'm getting better fuel economy than I thought too!

Just wondering

 

[SRadke]

Yep, that's what it means. If gear ratio's interest you check out the link that Klenger posetd here:





https://www.turbodieselregister.com/forums/showthread.php?threadid=94569



-Scott

 

[y-knot]

Yes it you have larger diameter tires then stock, you will be going faster then indicated by your speedometer. I am running approximately 10% larger tires and when my speedo indicates 60, I am really doing 66. You also have to multiply your mileage figure by the same percentage. For me, if I go 450 miles then fill-up with 30 gallons. I add the 10% to my 450 and come out with 495 actual miles divided by my 30 gallons of fuel, which gives me a 16. 50 MPG. You have also remember that oil changes and filter changes are effected.

 

[ata]

Yep your going faster then your speedo says you are. Best I can`t figure is about 3 mph off at 60 mph (speedo showing slow) 5 miles short every 100 miles.

 

[Duluth Diesel]

Ok, figure this one out. My truck came to me brand new with 265/75 16 tires. The sticker inside the door says 245/75 16. Did my truck come factory with an incorrectly calibrated speedo?

 

[SRadke]

Sometimes dealers will switch tire sizes upon customer request. It's possible they took the short tires off yours and gave you the tall ones from someone else.



-Scott

 

[Duluth Diesel]

Don't think so. I'll pull my window sticker out of the glove box tonight and check. I seem to recall that the window sticker (VINs matching my truck) showed that my truck was to get the 265 tires. But why the door sticker says 245 confuses me. Gotta love the quality control.

 

[Brand-X]

Hello I just put some 245/70/19. 5s on and this is the most informative tire calculator I have found... George

 

[DKayser]

Yeah Baby!

Originally posted by Brand-X

Hello I just put some 245/70/19. 5s on and this is the most informative tire calculator I have found... George

It confirms what I thought about my speedo error. Very Cool. Don.

 

[klenger]

The door sticker on my 01. 5 stated that the truck had 245x16 tires, but it was delivered with 265's. The spedo was right on, the door sticker was wrong.

 

[Slick]

This is another good tire caculator site. It lets you compare size and tells you the speedo difference.



http://www.miata.net/garage/tirecalc.html



Site comes up slow give it a second or two!!

 

[JHerrlich]

245's are what came on the base model. They don't bother changing the door sticker for the 265 tire option. I ordered mine from the factory with 265's and still got the 245 door sticker.

 

[Duluth Diesel]

This is why, with 315s, I trust my GPS for speed and let my speedo lie.

 

[Brand-X]

Originally posted by klenger

The door sticker on my 01. 5 stated that the truck had 245x16 tires, but it was delivered with 265's. The spedo was right on, the door sticker was wrong.

I learn something new every day this is why my speedo is right on with the 265s thanks again TDR and klenger... George

 

[johncameron]

I guess i should check the actual speed beside another vehicle to be completely sure. You guys have me wondering now! Thanks

 

[y-knot]

It isn't that hard to figure out, and the pertect change is accurate. I have two trucks that are both off, One is off by 10% and the other by 16%. I useually just do a quick conversion in my head, but if I have the GPS with me, it will tell the truth. If you do not have a GPS, don't woory the convertion by percent is accurate, just have to remember wich truck your in.

 

[Excessive Force]

Use the mile markers on the interstate,and compare to the odometer. Use a watch with a second hand.