MadocHandyman

I've got my odometer dialled in pretty close now using gps as well as the mile markers on the hwy. My speedometer is still way off though.
Is that normal? I thought these had electronic speedos but I guess mine is still mechanical.

BobSchuman

I did it with the tire size and the program asked for the info. Double checked accuracy with my phone gps speed ap. Hope that helps.

dasswright

Interesting. When I changed from the stock tire size to a 35" m/t on my 04 lariat 4x I went into the gear ratio on my u571 I believe it is. I changed it to 4:10 ish. I'm sure I should have done more research before going on and experimenting with things I don't know about. So anyway, after driving this way for 30 miles or so I didn't recall a major difference in performance but I noticed starting the truck occasionally it would turn over for awhile before starting.twice as many turns as normal and also my idle would get a little weird and very low. When first got tuner and running stock tire size I installed 91 performance tune and noticed a dramatic increase in power right away . Driving was great but at idle and starting things seemed not great/ healthy and I always end up retreating to factory backup out of fear I'm going to damage something.engine Trans drive train etc. recently encountered rear diff issues. Pinion and axle bearings going out with a hummish soft grind ne high frequency vibration. I was wondering how much my new tire size and my experiments with the gear ratio could have played a role in rear diff issues. Or it's just lack of maintanence or one of those standard issues... Been considering adjusting the NOV tire revs / axle ratio. Any thought or suggestions? Anyone . Thx for all the info . It's been very educational