As some of you may know, I am downsizing from a 17" Chrome Clad Alloy rim, to a 16" steel rim. Can anyone tell me, with just a standard aggressive all season tire, will I need to have the ECM flashed for the fuel economy and all other measures and things of the like to work right? Or, will it be fine leaving it as is?

-Officer1151

 

If you go back to a 215/55/16 you'll be right at the stock size for the 16's. No need to reflash the ECM, Stiglitz won't even notice the difference since the diameter will be unchanged, and even the width will be the same. As for tires, I'd think maybe the Goodyear Eagle GT's or the Continental Extreme Contact DWS tires. Both are getting good reviews by folks here, and they seem to be a good compromise between performance and everyday use. Around here the GT's are running about $115-120 each and the Conti's are going for just about the same price. Check out Discount Tire or Tire Kingdom.

 

I have a hook up at a tire place here I think. We'll see what she has to say. :)
Even though mine now are 17" if I go to the size and specs you listed, no need to flash the ecm? really?

 

Really, as long as you stick to a stock size you'll be at the same overall diameter, no changes needed. Its when you start going significantly larger in diameter or smaller, that's when you get into issues with speedo calibration, ABS speed sensors being out of range, and unhappy traction control....then you have to think reflash. For all intents and purposes the 215/55/16 tires and the optional 215/50/17 tires are identical in section width and overall diameter, only thing that changes is the diameter of the wheel.

 

I've got two sets of wheels, 16 inch Euromax 612, and the 17 inch polished aluminum factory wheels. ('07 was not "chrome clad") Goodyear Eagle's on both.... 225/50 ZR17 and 225/55/R16 sizes are virtually the same in over all diameter and width so the car doesn't even know they's been changed as far as ECM, ABS, etc..... There is a ride difference, 16's are smoother, but not even much handling difference unless I were to go racing. Check your tire size calculator ( Tire Size Calculator ) and find a size that's going to closely match your existing diameter

 

So, on the same note, if I was to upsize from my 1LT wheels to 2LT wheels, with the 2LT-size tires, there would be no speedometer inaccuracy, issues, etc. You're basically saying that either way, it's the same diameter. But with the 1LT, it's a fatter tire, smaller wheel, and 2LT is bigger wheel, smaller tire. That makes things simple. I would like to get some 2LT wheels for summer wheels, and keep my 1LT wheels for winter. I was wondering the same thing before this thread...

 

Either way it's the same if you get the proper size tires...... 1LT and 2LT have a different over all diameter stock, as far as I know, so when moving up or down if you don't choose the correct size tires you can throw off the speedo and possibly stability control, (if you have it) ABS, etc...... 1LT and 2LT are not a direct swap, and nowhere did I say that in my previous post.... I don't think anybody else did either. (EDIT.... My Bad. 843 did say this....)


The point is wheel size is unimportant if you keep the same over all tire diameter the same.

 

Hmm interesting. That's good to know. Thanks. 843, do you just stalk stats on vehicles?

 

Most people on here looking to switch wheels/tires use something like this:
http://www.miata.net/garage/tirecalc.html

 

Not really 1151, but being in the heavy equipment business you get to know and remember all the specs on everything you deal with. When you're trying to get someone to part with say 450k for a piece of equipment, gotta know everything about it, same for ordering stuff for inventory. I've always had one of those weird minds that is like a sponge, read something once and its locked in, went through law school without ever carrying books around....read 'em once and the info is in there for good. Used to win lots of bets at bars because I could remember every license plate in the parking lot.