wyominghotwheel said:You will probably be off a few miles an hour, but just learn what the difference is and keep your cruising speed there.......if you are going 50 and you know 47 mph is 50 in your car after the 17's, slow her down and go 47......
srothfuss said:If he adjusts the size of the rubber correctly then there should not be an issue with the speedometer. Performance wise you will loose a small amout, but you won't notice it. If you switch, You want the same overall diameter of rim/tire.
Now, when you move up in tire size correctly, that means more metal and less rubber. Which translates into more weight.This requires more energy to rotate the tires and that is where you will lose some power. (probably not really noticable) As a side note... Bigger tires take longer to stop because of the increased inertia so make sure your brakes are up to the challange also.
If you search google for "tire size calculators" they can be a great help to make sure that you don't throw off your speedometer or effect your gearing.
For me going from a 225/60/R15 to a 225/55/R16 or 245/45/R17 would give the same overal diameter of wheel so my speedometer would read correctly. But then my car would ride stiffer and stop worse so I am not ready for that move yet
powertrax91 said:the loss in acceleration is quite notiable... I lost .5 sec in ET when i went from 16x7 ponys to my 17x9 cobra Rs... the weight diff. is huge
powertrax91 said:the loss in acceleration is quite notiable... I lost .5 sec in ET when i went from 16x7 ponys to my 17x9 cobra Rs... the weight diff. is huge
tjm73 said:Totally true. I went form easy 13.8's to 14.4's when I switched to my new wheels from my old draglites. Nothing else changed.
On the street things feel very similar almost can't tell a difference. Liek soem one else said the wheel size doesn't effect the speedometer reading, it's the tire height.
i wouldn't say it's totally the weight if the only thing changed was the rim size. if you didn't change the tire diameter than you lost some sidewall and .5" all the way around is a significant amount. how i understand it is, the more sidewall you have the easier it is to hook up cuz the energy has more material to spread throughout. so i'm guessing that you're 60 foot was worse.powertrax91 said:the loss in acceleration is quite notiable... I lost .5 sec in ET when i went from 16x7 ponys to my 17x9 cobra Rs... the weight diff. is huge
You also could just use Google to compute tire height. It does computations directly through the search.vristang said:I created an Excel spreadsheet for calculating what the speed and rpm differences would be.
Only a Nerd would think this was as cool as I think it is.
are your cobra rims made out of lead, lolpowertrax91 said:the loss in acceleration is quite notiable... I lost .5 sec in ET when i went from 16x7 ponys to my 17x9 cobra Rs... the weight diff. is huge
GRGT1994 said:You also could just use Google to compute tire height. It does computations directly through the search.
For example, enter "255 millimeters multiplied by 45 percent multiplied by 2 plus 17 inches in inches"
When you hit search, it will tell you that equals 26.0354331 inches.
Kinda neat.
GRGT1994 said:I think the descrepancy you mention could be caused by a number of things. Tread wear is surely one. But probably more importantly is how tires dimensions are computed to begin with.
I would imagine the 255/45/17 dimension does not contemplate the distance from the ground to the top of a tire mounted on a wheel, at pressure, supporting a car. There are too many variables there within the range of potential applications for any given tire. So the advertised measurements are probably off the wheel. And then all those variables mentioned above (plus vehicle weight and wheel width) will add to the variance you mentioned.
So any calculation off advertised dimensions will, of course, only give you some hypothetical information to work from. But you still should be able to make some useful comparisons among tires based on a strict, cold calculation.
super302 said:are your cobra rims made out of lead, lol
My cobra rims didn't feel any heavier than my shtty turbines
There is prob a 5 pound per wheel dif, and extra 20 pounds isn't going to slow you down, its has to deal with traction and tons of other factors