I finally received my set of Amer Racing Atlas chromed wheels (17 x 8 with a 7 lug x 150 pattern and 0 offset with 4.5" backspacing). These are the only chrome wheels on the market that fit the '06 HD F-150 that I could find. That's OK though, because I like the wheels.

Question: What's the largest tire I can put on my 4x4 using this wheel without changing the speedometer calibration? The reason I ask is I want to keep the orig equipment steel stock wheel / tire combo for use in the winter (brutal on trucks up here), and change to the new AR's each Spring. (The OE tires are 245/70R17, which have a calculated diameter of 30.5") .

Would, say, 285/70's, which would have a diameter increase of 2.2" give me an unresonable speedometer error?

:o

 

If you do not want ANY change on the speedometer then you need to go with the factory tire. If you would like a slightly larger tire here is a handy calculator that you can play around with that will show you the difference in your stock size and the other sizes you are looking at. If you purchase a tuner you can put almost any other larger size and adjust the speedometer with it. I believe up to 40 inch tires. Anyway, here is the link for the calculator.

http://www.1010tires.com/TireSizeCalculator.asp

 

Thanks TX-FX-4. The calculator is a great timesaver.

What is a tuner? Any idea how I'd get one? (I've seen on this site that it costs up to $80 to recalibrate the speedometer at a dealership). If it wouldn't void the warranty by changing the odometer reading or something, I'd be interested in getting one.

 

A tuner is a flash device that reprograms your PCM(Power Control Module) on the truck. This is the Computer that monitors and regulates engine activity. A tuner(computer) helps to not only maximize the engines efficiency(some instances giving you better gas mileage) an increase in power. It also helps look at trouble codes your truck may get like the check engine light. Why is it on?? put the tuner and it will tell you where the errors are and allow you to clear them if needed. It also allows you to recalibrate for a change in gears(if you change them) or change in tire size. For example I had 33 inch tires and the factory were 32. My speedometer was off by 3-4 MPH so I used a tuner to tell the computer I had different tire size and it compensated. Also, because of the bigger tire, I kept blowing speed sensors in my rear differential and my ABS light was coming on, because the revolutions of the tire were different from factory and was throwing my system off. I originally wanted the dealer to address some throttle response issues and calibrate the tires and they could not do it. They said they did not know how and supposedly my truck had the latest calibrations. Even though the (TSB)Tech Service Bulletin was addressing my trucks build date. Anyway it is a pretty nifty device but is expensive for some 329-399(appx). It is considered by many to be the best bang for the buck for our trucks. For versatility, looks and price I went with the Edge Evolution. It offers gauges and digital readouts, temperatures and miles per gallon(when hooked to your vehicle). Or you can tune your vehicle and remove it when done reprograming. I calibrated for Octane level I was using and for my larger tires and it has really improved the power and response of my truck. You can read about it here.
www.edgeproducts.com Good luck.

 

Well,TX, thanks again. I think you've identified my birthday present for the coming year. The dash mount looks great too. Expensive, but what a great toy!

You've been a great help. Cheers!

 

Welcome to the Forum. I'm sure you will help someone some day as well. Good luck. There is alot yet to learn.

 

while the tuner is the ultimate... if you dont want to dish that out quite yet, the dealer can update your data in the pcm to the new tires for $20-30. they did mine when i went up in size. find out your tire statistics (usually from the company who made them) and find the Revolutions per mile- take that # around 600 something- to the dealer, and they will put it right on.
rock on, welcome to the board.
Justin

 

Thanks everybody. Actually, if the tires are big enough, my wife won't yell at me for going too fast on the interstate, because the speedometer will read 8 MPH. I think I see a bright side to this.