Moderator: volvite
To answer my own question, the service department I visited today said that they can't reprogram the speedo. It was quite a team effort in finding that answer, with the conversation ending up with talk of the vaporware 5" Calmini lift & larger tires. Wonder how they'll react when I bring it in with the modest OME lift installed.NVSteve wrote:Thanks. Sure makes it that much easier for me to decide. What are the odds that the dealer can re-program the computer to compensate for the tire change? Has anyone tried this? I can live with the mileage being off, as I've had to do that in almost every vehicle I've ever owned. But, it would be nice if it could be corrected.RacerZX wrote:No hesitation at all.
Man, do you have your old wheels? Or could borrow a set from someone else, so you can get the true results. Or you going to have to redo all the other tests, with the 33s..RacerZX wrote:One minor downside with these bigger tires is the hit on straight line performance. Sure it's a bit slower due to the gearing change (taller tires = taller effective gearing), but I was surprised to find how much the added weight and rotational inertia effected things. I just had the truck on the Dyno this last Saturday before installing a Gibson exhaust and found only 300HP at the wheels instead of the previous 320.
Now a different dyno on a different day will show some differences, but 20 is beyond the margin of error, and that was only spinning two of these monster tires.
Gibson write-up to come soon as I can get back to the dyno to do a follow-up test...
I was pretty set on the 285's until a thought popped up out of nowhere. If you have made things so that the tires *just* clear, I'm wondering about those situations when the off roading consists of dirt/muck that adheres to the tires. With little clearance between the wells and tires, I could see mudflaps snapping off and wells getting scratched & scraped through the first layer of plastic. At the absolute closest, what kind of gap are we talking about between tire & well?RacerZX wrote:I'm using my stock wheels with the bigger tires, so no, there's no going back. It would be amusing to do before and after dyno runs to see exactly how much the bigger tires loose you in power, but I can't easily do that at this point.
Says the man from California.RacerZX wrote:It's pretty darn close, depends on how good a job you do with the heat gun redefining the fender liners. That being said, I have a hard time imagining anything sticking out of the tread far enough and solidly enough to cause damage that isn't already causing you precipitous air loss.
See, I hadn't even thought about that. I've only been thinking about tire sizes in an road/off road context. That may be too tight of a squeeze with winter buildup under the wells. I guess I'll just have to take a closer look at the situation now, then try and envision how to improve upon it for something larger. I'm all about the heat gun, but I wonder if there would be a more effective solution. Maybe removing the molded flaps and replacing with rubber? Decisions, decisions.amr40509 wrote: Says the man from California.
Be careful if you run in below freezing conditions. Ice can bridge that gap when you park and freeze the tire to the "other" surfaces...then you might get some snap/crackle/pop effect.