I recently purchased new tires for my 2004 Chevy 2500HD 2wd and got a
slightly larger size - specifically LT265/75 R16 versus the old tires at
By using my GPS as a control, with my old tires the speedometer would
indicate 70 mph and the GPS would indicate 68.5 mph. With the new tires
when the speedometer indicates 70 mph the GPS indicates 71.5 mph, so there
is approximately a 3mph difference at 70 mph indicated from my old tires to
my new ones.
My question is, will this difference cause any major issues with the ABS
and/or the engine management systems. Will the ABS be more or less prone to
activate under the same conditions as before, and will it noticeably effect
my mileage or cause any problems with the engine and transmission (Duramax
diesel and Allison 5-speed auto)?
Thanks for any insight.
Cheers - Jonathan
I don't think it'll have much effect, but you can get a power programmer and
program the tire size in to correct the problem! You can usually do this
for Chevy's. Fords for example never seem to give you this option. It's
not a cheap fix, around $400, but since you have a Diesel, a Power
Programmer will make a pretty big Improvement in HP and Torque also. Quite
a bit more then a Gas Engine.
Thanks for the suggestion, but $400 isn't in my discretionary spending
budget just yet... Even so, at the HP and torque this motor is putting out
stock while still getting 20mpg in mixed driving I don't need any more power
and don't want to jeopardize my mileage.
I could take it to the dealer and have him reset the ECM for the new tire
size, but that is a matter of having the time to give them the truck for
half a day - which currently I don't have available in my schedule.
I guess what I should have clarified is will the difference in the new
tires' size cause any problems with my ABS and drivetrain until I can get
the computer reset (maybe 3-4 weeks)?
Cheers - Jonathan
Increasing the performance will not screw up your Mileage, will unless you
start getting on it afterwards because of it. As long as all the tires are
the same size, it's not going to effect your ABS at all. Getting larger
tires is done all the time. I've done quite a few lift jobs on brand NEW
dealer trucks which end up which much larger tires then stock with no ABS
problem. The Speedo will be out a wack a bit, but nothing major. Go here
and check out some Info. You'll be surprised. Increased Mileage!
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