Tire Specs

what does the first # signify in tire specs...

i'm looking at tires that are 255/50/20 and 285/50/20 and i'm trying to figure out what the difference will be in the tires visually.. i know the 50 corresponds to the width of the tire from the outside of the wheel (rim) to the edge of the tire, and the 20 corresponds to the size of the wheel the tire is for...

 

The difference in the two tires will be barely noticeable. The 285 is simply a little wider a tire than that of the 255. These are measured in metric numbers. I believe it is millimeters, but it may be centimeters. You can easily check which one by measuring, yet that is really not relevent. I hope that helps. Choose the width according to what it is you need the tire for. Remember that the wider you go, the less pounds per square inch that is applied to the road, and thus less traction in wet and snow conditions. Aslo be sure that your rims will be the right size that can accomodate both sizes of tire. You wouldn't want to buy a bigger tire only to find out that your rims won't allow for it. Good Luck

 

thanks hairman...

 

Check out this website, it has a calculator that will help, tire width affects tire height thus it affects speedometer readings.

 

I hear ya MiDGeT.Rolln' on yo 20's.

 

255 is the tread width, 50 is the percentage of sidewall of tire relative to tread width. For example, if the tire is 255 wide then the sidewall is 127.5mm high. And the 20 is rim diameter in inches.

 

here's my truck:

http://img.photobucket.com/albums/v180/ANHEDONIC/Explorer.jpg


here's the RIMS i want to get:

http://www.aewheel.com/images/categories/301_20chrome.jpg

Boss 301's


here are the RIMS on a Explorer Sport

http://img.photobucket.com/albums/v180/ANHEDONIC/xbeach.jpg


here's a similar looking Explorer with a similar style wheel

http://www.zinikwheels.com/IMAGE/rides/explorer.jpg



i found a reputable seller on Ebay to get the Boss 301's for like $900... need to look into tires, thinking about Goodyear Eagle GT II tires, 285/50/20... i won't be doing this for at least 6 months but have been doing the research lately....

 

The speedometer can be recalibrated to compensate for different tire sizes, up to a limit. If the tire is considered too much larger than the vehicle manufacturer recommends, then it likely won't be found on the calibration table. Some, you can manually calculate the new spec. Regardless, you need access to a scan tool, or pay the dealer. When we encounter the oversize tires at work we set them as close as possible.

 

Specification Sidewall Radius Diameter Circumference Revs/Mile Difference
255/50-20-------5.0in-----15.0in-----30.0in------94.4in-----------671---------0.0%
285/50-20-------5.6in-----15.6in-----31.2in------98.1in-----------646---------3.9%

http://www.miata.net/garage/tirecalc.html

 

Truck eh? How about gas guzzling, road hog of an SUV for short? http://forums.majorgeeks.com/images/smilies/wink.gif

 

Your truck will definitely look phat once you get those rims.

 

I will never understand why a guy has to put down a negative comment such as "How about the gas guzzling....", when a guy is simply writing about somethng he is happy about. Do people like you have no better things to do?
Geez, give the guy a break. I personally love your truck. It looks good. I wish I could afford something as nice as that.

 

thanks for the positive feedback guys... i will definetely take a bunch of pictures when i get this done LATER down the road...

 

Billions of dinosaurs died to become that oil. He just doesn't want their deaths to be in vain.

 

now that's just funny.
Make sure you keep your steel rims. Low profile tires suck in the snow and slush of winter.