Is this really necessary?

[4RunnERD]

So I went to Firestone today to check the tire size availibilty for 265/65/18, which is one size taller than OEM for the 18" limited wheels and the guy started talking about having Toyota re-flash my ECU. I told him I understand that the speedo will be of a little and my gearing while change slighty with taller tires, but he seemed really concerned with the fact that I have all-wheel drive and thought a re-flash would be in order. Does this make since?

Why does everyone freak out the second a customer wants to deviate from a stock size, everywhere I go I get a lecture about it. I understand and can appreciate people wanting to make sure I am informed before I make changes to the OEM specs, but it's starting to feel like I am the first person to ever order a custom size tire in the state of WI!

 

[skyak]

short answer...no

 

[BlackWorksInc]

The AWD system does not need a re-flash to function with different sized tires, the speed reading may throw off some things, but in general it should not cause any issues.

 

[4RunnERD]

The AWD system does not need a re-flash to function with different sized tires, the speed reading may throw off some things, but in general it should not cause any issues.

Thanks for the response. I will be the first to admit I am no expert, and like I said I can appreciate people looking out for my best interest in terms of changing things on a vehicle, but after all the threads I have read on this forum about tire sizes, I was just really caught off gaurd by the re-flash comment.

 

[teampwr2]

I dont Have 18" wheels But I went from 265/65/16 to a 255/85/16 basically a 33" tire ,and My speedo is off almost exaxctly 5mph at 60 mph ,60 on speedo is really 65 and 70 is 75 as well .at about 35 its abot 3mph off ... I just used my garmin GPs to see the diff.
But No flash is required.

 

[Jerrydog]

I love that we have our own certified toyota tech! :bluejump:

 

[mnormand]

I love that we have our own certified toyota tech! :bluejump:

Yes!


I bought my last set of dual sport tires at Sam's Club, they wouldn't even consider installing the slightly larger set I chose. So I carried them to a tire shop, $80 later, I was still way cheaper than any tire shop in town for an installed set.

 

[Trevloc]

i went from 265/65/17 to 265/70/17, thus a tad bigger. they didnt say a thing about my speedo being off.

it doesnt start to be off til about 60 mph, and its only off by about 2mph. and once i get to about 80, im actually going 83. the faster you go the more itll be off. when i hit the highway i just turn on my gps.

 

[BlackWorksInc]

I love that we have our own certified toyota tech! :bluejump:

I can't be the only mechanic on the forum! I'm sure theres a couple people here who are dealership techs also. Lol