Tire Size Affecting Speed

[Vimugsy011]

Has anyone else seen a difference when changing tire sizes? I recently put on some 285 35 19 R888R's and seemed like it was slower, I could be crazy but it seems like when I swap to a custom summer tire size it is faster. Does anyone else experience this when changing tire sizes, the only option I can select in the menu is the stock size.

Sponsored

 

[SD_MK]

No.... probably just you, i'm on some Michelin 285/35/19's and spin a little more scarier than when i was on stock 275 PSS's.

 

[XtremeMaC]

 

[Loco38SUP]

Has anyone else seen a difference when changing tire sizes? I recently put on some 285 35 19 R888R's and seemed like it was slower, I could be crazy but it seems like when I swap to a custom summer tire size it is faster. Does anyone else experience this when changing tire sizes, the only option I can select in the menu is the stock size.

I don’t understand your statements. Are you saying that when you change the tire selection with the iDrive menu the car responds either slower or faster?

-RJM

 

[Loco38SUP]

No.... probably just you, i'm on some Michelin 285/35/19's and spin a little more scarier than when i was on stock 275 PSS's.

Which Michelins are you running? Its a little odd that 285 PSS are spinning more than 275 PSS.

-RJM

 

[Vimugsy011]

Which Michelins are you running? Its a little odd that 285 PSS are spinning more than 275 PSS.

-RJM

Honestly I feel that it has something to do with the computer, I was running stock tires before and put on the Toyo R888R 285 35 19.

If I change the idrive tire settings to custom summer tire it seems to accelerate faster than the stock size. I should do some test runs with draggy to verify the difference, just wanted to check and see if I was the only one.

 

[3TMagnetMan]

I think you should have gone 285/30/19s instead of 285/35/19s. The 285/30 would be close to OEM tire diameter. While the 285/35 would increase tire diameter would decrease revolutions per mile compared to the OEM sizes. Which in turn will change acceleration due to gearing of the vehicle. Tell me how I know I did something similar when I had a M3 and the car acceleration was slower. Also I have a FJ Cruiser stock came with 31 inch tires and am running 37 inch tires now that's a huge change in acceleration. To change this you would have to play with gears or change to a lower profile tire or increase power. Besides that the the speedometer will be off a few mph. Once you start playing with tires sizes away from factory spec tested tires sizes you will always alter the vehicles dynamics.

 

[Loco38SUP]

Honestly I feel that it has something to do with the computer, I was running stock tires before and put on the Toyo R888R 285 35 19.

If I change the idrive tire settings to custom summer tire it seems to accelerate faster than the stock size. I should do some test runs with draggy to verify the difference, just wanted to check and see if I was the only one.

Interesting observation, let us know what results you get from testing. It could be the transmission is responding different based on tire size input.

-RJM

 

[SD_MK]

Which Michelins are you running? Its a little odd that 285 PSS are spinning more than 275 PSS.w

-RJM

285 PS4S as temporary until my PSC2R's come in. But the PSS just wanted to drift. ??? the PS4S is scary just because it spins and sometimes either spins going straight or i had to correct relatively hard a few times, so yeah, kinda scary lol. The PSS were just super predictable lol.

 

[ikeaboy]

I replaced stock setup with Michelin Pilot Sport 4S 265/35-19 fronts and 305/30-19 rears over the weekend. I changed the iDrive settings to custom as soon as I got in the car then rode around until the TPMS adjusted. I immediately noticed better ride quality. I only drove in the rain so I didn't really get a chance to accurately compare acceleration vs stock. Wet weather traction has improved a lot when compared to stock.

 

[METAL]

I think you should have gone 285/30/19s instead of 285/35/19s. The 285/30 would be close to OEM tire diameter. While the 285/35 would increase tire diameter would decrease revolutions per mile compared to the OEM sizes.

No do not do this. 285/35 is closer to stock than 285/30.

 

[3TMagnetMan]

No do not do this. 285/35 is closer to stock than 285/30.

You are correct.

 

[jreinlie4]

The speedometer already reads slightly fast by a couple MPH. By switching to a slightly larger diameter rear tire it would actually make the speedo more accurate.

Sponsored