Does rim size affect the speed?

[GSRteg®]

Ok. I have a 93 Civic Hatch and it originally can with 13's on it. Now I put some 15's and wanted to know if it affects is. Lets say im going 40 would it bump me up to 50?

[JennB]

Are you talking about the accuracy of your spedometer? if so yes. But not just the rim size, the overall diamiter of the entire wheel. You can get smaller rims and then put tires with a larger sidewall on them and barely effect the spedometer accuracy. But say you go to a smaller wheel and a lower profile tire (or larger, either way makes a difference) and yes.

Put both of your tire sizes in this calculator to find out

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

[GSRteg®]

Tire Size Comparison


Specification Sidewall Radius Diameter Circumference Revs/Mile Difference175/70-13 4.8in 11.3in 22.6in 71.1in 891 0.0%195/50-15 3.8in 11.3in 22.7in 71.2in 889 0.1%It gave me this explnain?

[quickdodge®]

It means that you can go to a 195/50-15 without affecting the speedometer. Later, QD.

[GSRteg®]

Thanks

It means that you can go to a 195/50-15 without affecting the speedometer. Later, QD.

[Maniaç]

if your car starts out with lets say 185's and you put 225's.. it'll fuck up your sppedometer. you think you're going 50 but you're only going 40mph... not sure about anything else. this situation happened to a firend of mine, awhile back.

[Djlin]

so if i have 17's im not really going the speed my speedo says?

[Maniaç]

well this happend to an Altima. with wider tires... not sure about the Rim size.

[GSRteg®]

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

so if i have 17's im not really going the speed my speedo says?

[Frög]

Are you talking about the accuracy of your spedometer? if so yes. But not just the rim size, the overall diamiter of the entire wheel. You can get smaller rims and then put tires with a larger sidewall on them and barely effect the spedometer accuracy. But say you go to a smaller wheel and a lower profile tire (or larger, either way makes a difference) and yes.

Put both of your tire sizes in this calculator to find out

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

side note, i saw you driving on spalding crossin holcomb bridge yesterday..

[GSRteg®]

Thanks for y'all help.

[Hulud]

this should be in the WHEELS section

[Hulud]

anyways heres a simple calculation that can help

your tires WERE 175/70/13 and you went to 195/50/15

so heres what you do, convert 175mm to inches (175 x 0.039) = 6.825inches

then multiply your inches by 0.7 (the 70 shows that 70% of the width of the tire is the height of the sidewall) 6.825 x 0.7 = 4.7775

then you multiply that by 2 and add the 13 inches for the rim and you get the wheel height. (4.7775 x 2) + 13 = 22.555

so do the same for the new wheels and you want to be as close as possible.

195 x 0.039 = 7.605
7.605 x 0.5 = 3.8025
(3.8025 x 2) + 15 =22.605

so 22.555 compared to 22.605

you went a little bigger by 0.05 inches, which means that your speedometer will say you are going slower than you actually are (but in this case i doubt it will be noticable)

[twinj]

My .02 arent needed.

[thepolecat]

easier solution- go with the flow of traffic- not more not less.

[GSRteg®]

Ah, yes that explains everything.

anyways heres a simple calculation that can help

your tires WERE 175/70/13 and you went to 195/50/15

so heres what you do, convert 175mm to inches (175 x 0.039) = 6.825inches

then multiply your inches by 0.7 (the 70 shows that 70% of the width of the tire is the height of the sidewall) 6.825 x 0.7 = 4.7775

then you multiply that by 2 and add the 13 inches for the rim and you get the wheel height. (4.7775 x 2) + 13 = 22.555

so do the same for the new wheels and you want to be as close as possible.

195 x 0.039 = 7.605
7.605 x 0.5 = 3.8025
(3.8025 x 2) + 15 =22.605

so 22.555 compared to 22.605

you went a little bigger by 0.05 inches, which means that your speedometer will say you are going slower than you actually are (but in this case i doubt it will be noticable)

[cactusEG]

Ok. I have a 93 Civic Hatch and it originally can with 13's on it. Now I put some 15's and wanted to know if it affects is. Lets say im going 40 would it bump me up to 50?

no.. i have 15s and riding normal

[GSRteg®]

Got it.

no.. i have 15s and riding normal