I had my dealer install 265/70 R17s instead of the delivered 265/65 R17s on my 2004 SR5 V6 4WD 4Runner at tire replacement. I did this to gain about 1/2 inch in ground clearance but primarily to give additional sidewall height to ballon out at low tire pressures providing better footprint for operating off road in deep soft sand.

I quized the dealer if it might be worth a reprogram for performance and was told not to worry about it. Of course I know the speedometer/odometer is off about 3 % and there is affect on the mileage remaining vs gas in the tank calculation.

I see no real change in performance but would be interested in any comments.

Surprising comment from the dealer, I think. The larger tires will also effect the timings on gears changing. It might not be much but it does effect it. I've had it done and it ran about $80 and I thought it was worth it.

Thanks for the comeback. Why I came here for opinion. Like going to the doctor, sometimes you need a second opinion. Actually this dealer is very good because they generally are fairly honest with recommendations that will cost you and I suspect that was driving the answer. Me I like things tweaked so I'll probably go for the reprogram since I expect to keep the vehicle until it dies.

I think you'll feel happier about things in the long run for having it done. That way, every thing is the way it should be especially if you sell the vehicle.

What vehicle did you have the reprogram done on and was the reprogram done by a dealer ????

Land Cruiser and yes, it was done by a dealer.