Will 215/65/r15's work on a justa clubman that came with stock 175/65r15's? I'm worried about binding/rubbing and the Speedo will be correct with the larger tires, as the dealer told me that the bigger size will read 65 when you are doing 71, as my speedo is now reading 71 when actually doing 65! If they fit and don't rub, it's a win/win.

 

The width of the tire has nothing to do with the rotational speed (and the resulting odometer and speedometer readings.)

The two tires have the same sidewall height and the same rim diameter. Thus, they will (allowing for manufacturing tolerances) turn at the same speed.

The wider tire may rub on the bodywork or suspension, however. You will want to check that out very carefully before purchase.

--
Darryl

 

First of all how do you know your speedo is off by 6MPH at 60 miles an hour? the normal is about 2-3 MPH.

Are you currently running on stock OEM tires?

Actually if you go to the 215/65-R15 then you will be increasing the error in you speedo by a lot, as you will be increasing the diameter from 24.2" (approx) to 26.1" approx this is a very large increase and would put you speedo off by probably about 8.5% more (slower than the speedo reads).

So if you want to go from a 175/65-R15 to a 215 wide tire you would really want a 215/55-R15 This changes you from approximately 24.2" diameter to a 24.5" diameter. Which is getting the speedo accuracy closer to the actual speed.

But please note that the 215 wide tire will not fit on the rim that the 175's fit on. At least not properly.

Just note each manufacturer and model will have slightly different diameters. You really want to keep the final diameter about 24.5" that will give you the closest speedo accuracy.

There is a lot of information that goes into tire sizing and it really does make a difference in the long run to know how it will affect you car and its handling.

I run a 215/40-R17 tire on my car and do not have rubbing issues. This is not to say that you will not.

It all depends on the tire and rim combination and the offset of the rim to much/little offset and you will rub inside or outside.

 

Not quite. The 215 will be taller. The two tires have a 65% aspect ratio, but the 215 being wider is taller too. That is a pretty big jump and may be too big.
http://www.discounttire.com/dtcs/infoTireMath.dos Try this out and see what you think. I have heard the 215 will fit, but haven't seen any, of course I don't get to see to many Minis around here

 

This is very true

This is very untrue. The side wall number is a ratio of the width of the tire. So with a 175/65 tire the side wall height is 4.5 inches with a 215/65 tire the side wall is 5.5" or to look at it another way the diameter of the 175/65 is 24.2" and the 215/65 is 26" or 1.8 inches larger. And the circumference change is from 73.5" to 81.7 inches, and the number of revs per mile changes from 842 to 776. Big differences.

This will greatly depend on the offset of the rim. If it you set up the right offset then you will not have a problem.

 

These are Michelen's from Costco, and I have a $70 dollar off coupon. They will be ordered, as they have none in stock.

Now: 175/65 = 23.96" dia
= 6.89" wide

Afrer 215/65 = 26" Dia
= 8.96" wide

My concern is rubbing, yes they will fit the rin, altho not spec.
As for the speedo, yes it has been checked with Radar, 39mph is 35, 50 is 45, 71 is 65. I took this up with the Mini Mech who was updating my computer to fix the famous window problem, and he said they are not allowed, or even trained on how to fix the speedo, as they don't let them know what's in the comp. Sounds alot like Toyota (Rolls eyes) and that they all come that way, but on Costco's computer it said thet the normal reading of 65 would actually be 71, and thats how much it is actually off.

 

What rims are you running. If they are OEM rims for the 175/65 R15 then I would not put the 215's on those rims you will have nothing put problems as the beads will not seat properly. The rim is to narrow.

Yes there is nothing that the MINI mechanics can do, unfortunately it is not even something that can be changed.

As for the radar i am not sure if I would trust that all of the radar guns where is live are rather inaccurate.

Test the speed against a GPS much more accurate than testing against a radar gun.

As for what cosco says I would not believe any of it. IMHO those are the guys that can not get jobs at real tire place. I would be willing to bet that the 65 to 71 is for the new tires not the old ones. and if your speed is off by that much now then with the new tires it would be more like actual speed is 59 and speedo states 71.

Going from a 23.96" diameter to a 26" diameter will cause you all kinds of error with the speedo so expect that the error will be a lot worse. It will also play havock with your odometer as the odometer will also be very very inaccurate.

 

I am striving to make this speedo accurate, as I am terribly afraid this thing is putting more miles on than I am actually driving, not that I put a bunch of miles on her, as it just passed 6000 miles today, but anything electronic that is not correct drives me nutz!!!!!!

I really wish they made steel chrome slotted Mag disks like from the early '70's for this car, as I am terribly "Old School" and very **** retentive about cars. I would love wider tires on this Mini, as I think they would look great.

 

If the error on 195/55-16's is 3% as reported, then the error on 175/65-15's is going to be 4.9%, or 65 mph at an indicated 69.875. Although I don't see how one can reasonably adjust the speedometer with tire size except to reduce the error to 0.9-1.7 percent with 205/60-15's. Worrying about that amount is beyond **** as the difference between a new and worn tire can account for 1.5% error.

Personally, I'm going to spend $100 for a gps navigator and use that as a speedometer. I understand the problem with an optimistic odometer affecting resale value, but at my age I'll just be happy to outlive the car.

Your mileage may vary.

 

Well by changinig from 175/65-R15 to 215/65-R15 you will be changing the error by more than 8%. This is getting farther away from what you are trying to accomplish. Your Speedometer will be farther off than it is now. The car is designed to have tire in the 24" - 24.5" diameter range. Bumping this by 1.5" to 2" will cause your error to be even father off.

 

This is very true

This is the best and easiest way to solve this problem.

 

"The car is designed to have tire in the 24" - 24.5" diameter range. Bumping this by 1.5" to 2" will cause your error to be even father off.The car is designed to have tire in the 24" - 24.5" diameter range. Bumping this by 1.5" to 2" will cause your error to be even father off."

I do not understand this statement. According to on-line speedometer error calculators, a larger diameter tire will give a slower speedometer reading thereby reducing the error stated in the OP. A larger diameter tire travels further per revolution speeding up the car, but not the speedometer. N'est pas?

 

You -- and schatzy62 -- are correct. I'm not sure where my head was when I wrote my reply. Sorry to have introduced a red herring into the discussion. I'll try to think a little more clearly next time.

--
Darryl

 

YUP. my stock tires are off by over 4mph sometimes... I have larger-than-stock size for winter and i am now closer by 2mph.

In this case, the larger the tire, the closer youll be to "correct" speed


I guess the statement quoted in the quote could still be true, it just might surpass the "correct" point and then youll actually be driving faster than it says... vs actually going slower than the car says..

 

What you are saying is correct here the OP will go past the point of being close and end up traveling faster than the speedometer states. I.E getting himself into even more trouble.