Tire size changes???
Junior User
Joined: Jul 2002
Posts: 83
Likes: 0
Tire size changes???
Hi,
I recently bought a stripped down 98 Explorer 4 dr (xl model)which comes from the factory with 225/70 R15s. I would like to put on a set of 235/75 R15s as a minimum because the current tires look too small for the vehicle. Since the 235/75 R15 is the standard size for the other models, this change shouldn't effect too much.
Any ideas???
Thanks
-Rob
I recently bought a stripped down 98 Explorer 4 dr (xl model)which comes from the factory with 225/70 R15s. I would like to put on a set of 235/75 R15s as a minimum because the current tires look too small for the vehicle. Since the 235/75 R15 is the standard size for the other models, this change shouldn't effect too much.
Any ideas???
Thanks
-Rob
Elder User
Joined: Sep 2000
Posts: 580
Likes: 0
From: Kelseyville, CA
Tire size changes???
It will affect the speedometer, odometer and the shifting of the transmission. Ford can recalibrate the computer to account for the taller tires though. They charge about $75 to do it and not all dealers are equipped/capable of doing it.
Senior User
Joined: Apr 2002
Posts: 265
Likes: 0
Tire size changes???
It shouldn't throw things off too far since it's not a real drastic change. Put 'em on and see how it drives and then you can decide if you want to have it recalibrated or not. I had an old Bronco II that I out 235/75s on and I never had it recalibrated and it worked great for me. Just my $.02 worth...
Elder User
Joined: Sep 2000
Posts: 580
Likes: 0
From: Kelseyville, CA
Tire size changes???
The difference in tire sizes is 5.5%. When I went from my factory 30" tires to my current 31.7" tires (5.7%) on my '97 there was a definate difference in the shifting of my transmission as well as my speedometer. It's hard to describe, but the transmission just couldn't seem to find the right gear. Driving around town, the transmission would constantly shift up and down at about 45-50 MPH. My speedometer was also off by about 5%. Once I swapped the speedometer gear, the transmission shifted the way I was used to. On an older BII, the computer didn't have nearly as much to do with the transmission and how it shifts. Nowadays, the computer takes into account RPM, speed, engine load and temperature when it decides when to shift. Throw one of the parameters off and the computer gets confused. The difference isn't drastic and probably won't cause any harm but you will likely feel the difference.
Junior User
Joined: Jul 2002
Posts: 83
Likes: 0
Tire size changes???
Thanks for the input. I'm not too worried about the speedometer being off slightly. I have a 3.73 rear end so the larger tire size shouldn't put too much strain on the drivetrain. If the transmission shifts strangely, I'll get the speedometer adjusted.
Now its off to the junkyard to get some different wheels and try to find some seats to replace my vinyl buckets.
Now its off to the junkyard to get some different wheels and try to find some seats to replace my vinyl buckets.
Elder User
Joined: Sep 2000
Posts: 580
Likes: 0
From: Kelseyville, CA
Tire size changes???
3.73 is the tallest ratio offered by Ford with the 235 75/15 tires so power won't be a problem. My '97 has the same overall ratio now with my 32" tires and 4.10 axle. I noticed a little drop in off the line acceleration but it wasn't bad and still gets away pretty good.
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