OV TUNE/REGEAR?

im looking to upgrade my tires to 285/70/r17s. what do you people think. should I regear the diffs or get a OV tune

 

Regearing without being able to calibrate the speedo can cause issues depending on how tall a gear you use. People with 5.29s and I think 4.88s have reported the speed limiter kicking in on the interstate at traffic flow speeds because the truck thinks you doing 110mph. With OVT you can put in your tire and gear size and it will correct the speedo. Some have even said they were going to regear before they tried OVT and ended up not needing to after the (automatic) transmission sorted itself out and the big increase of non peak power. Your call

 

OVtune does not correct the speedo, it just changes shift points to accommodate new gears/tires.

 

I stand corrected. I thought there was a long discussion in the development thread about being able to correct the speedo, or is that one of the last few 2.0 upgrades that isn't ready yet?

 

how do 3rd gens read tire speed? larger tire size would counteract the lower gears putting speedo closer to stock. going up 10% tire size but going with 10% lower gears would just cancel each other right would it not. going 33s and 4.88s would have speedo around 10% off i think

 

Gearing doesn't affect the speedo. The speedo gets its reading from the wheel sensors and how fast they're turning. Bigger tires means the truck is going faster than indicated and has more miles than indicated if I remember correctly. OV Tune doesn't have a way to calibrate bigger tires. You'll need a speedo healer but as far as I know they don't have one that works with the 2019+ trucks.

 

After going to 285/70/17 tires, my speedo is pretty damn accurate. Using my phone GPS and the police radar signs they setup...its always exactly what the sign says or 1mph off.

 

It was a misunderstanding of why there was code referencing tire size, stemming from OVtune discussing the code they did not fully understand yet and speculating that it could be for the speedo. But it was determined to be a calculation of final drive ratio therefore changing shift points.

 

ok. 1st gen is read from transfer case so Regearing usually puts them back fairly close. if not u just have to swap little plastic gears on the sensor

 

Gearing first without a doubt. I own both. Make sure to 5.29s and not 4.88 if you are automatic.

 

4.88 and OVTUNE

 

For what its worth, I have 5.29s and 35s, and my speedo reads 5 miles off at 60 mph ( so im going 65)

 

The rough country and hypertech websites says this doesn’t work with 2wd drives has anyone tried this and does it work? Thx