dja5004

I am looking to install 295 65r20s on my 2015 F250. From what I have read, they should fit without any rubbing. If anyone has experiences, please let me know. The stock tire set up is a 275 65r20 and has a height of 34.1", the new 295s have a height of 35.1". Will this be enough to affect the speedometer?

From looking around, I have only found HyperTech's inline Speedo Calibration to be able to adjust it. I currently have a SCT programmer that does not allow me to adjust for tire size.

Any tips or help would be greatly appreciated.

Thanks.

JerseyGray

The difference will around 2 mph. I wouldn't worry about it

marshallr

Your new 35" tires will be 34" tall, after you have about 40,000 miles on them. Even if you could calibrate for the new tires your speedometer won't be right as the tires wear down. This is nothing new. All tires are approximately 1 size smaller when they reach the end of their life and always have. The accuracy of the speedometer has always fluctuated as they wear. It's just that before people had GPS's they didn't always know it. Anytime the speedometer is within 5% that is about as close as possible. If someone were going from 29-30" tires up to 35" then it would be enough difference to matter.

My son works in electrical construction and commutes 50-75 miles each way to construction sites. He'll work the same site for months, then move to another when that project is completed. A couple of years ago he told me that he'd been driving EXACTLY 100 miles round trip every day for months, but for the last week it was suddenly only 95 miles round trip. I pointed out that he had just bought new tires for his car and even though they were the same size, they were larger in circumference and that effected both his speedometer and odometer. In this case it was easy to calculate that everything was off by 5%. Actually it was then accurate. Because his tires were near the end of their life he was getting readings off by 5%.