Different Tyre aspect ratio on one wheel

apole · Post by **apole** » Mon Feb 04, 2008 12:20 pm

Hi there,

Just checked my tyres and realised that one tyre is different from all the others.

3 are 215/70 R15's and one is 215/65 R15.

This is on a 2wd.

I take it I should be getting the different one changed so it matches the rest?

Andy

bigdaddycain · Post by **bigdaddycain** » Mon Feb 04, 2008 12:36 pm

You can't be too careful with tyres andy,who's to say it won't affect the balance of the vehicle? Plus, i think it may be illegal (one axle,one size).

I'd stick the 65 section wheel as a full sized spare, (limited use then if used) A replacement bongo steel wheel can be bought for about £2 (without tyre) Then,say £40-£50 for a new tyre? Probably cheaper than the fine and three points if you get a tug...

scanner · Post by **scanner** » Mon Feb 04, 2008 12:55 pm

Do you have a full sized spare already? Or still have a S/saver?

If full size what size tyre is on that?

apole · Post by **apole** » Mon Feb 04, 2008 1:01 pm

No I have a space saver.

Gonna hit the phone and see how much a matching tyre is as it's not worth taking the chance.

Can't believe I didn't spot that earlier, must be getting old

Thanks for your help.

Andy

bigdaddycain · Post by **bigdaddycain** » Mon Feb 04, 2008 1:28 pm

scanner wrote:Do you have a full sized spare already? Or still have a S/saver?

If full size what size tyre is on that?

Give apole some credit scanner,surely that'd be the first thing he'd check if he had a full sized spare...

Apole? Seeing as that tyre has been on for god knows how long, there could just be somebody on forum in the same boat as yourself,but has a 70 instead of a 60?.... Pop it onto the stuff wanted section for a swap? You never know...

apole · Post by **apole** » Mon Feb 04, 2008 1:36 pm

Hi,

Thanks for the advice. So far only 2 places I've called can get hold of the correct size. Prices so far are £60 all in, but needs to be ordered in overnight.

I'll get this and then a tasty set of alloys with tyres will come up !!

Better to be safe than sorry though.

Thanks again, may have a tyre going soon if anyone is intersted.

scanner · Post by **scanner** » Mon Feb 04, 2008 1:49 pm

bigdaddycain wrote: Give apole some credit scanner,surely that'd be the first thing he'd check if he had a full sized spare...

BDC Fair comment, BUT plenty of other posts on here have lead me to ASSUME nothing anymore.

I could have assumed he would no longer be risking having to use a space saver, couldn't I?

My initial thought was that a previous owner might have needed to use the (full size?) spare and that it was the one with the wrong sized tyre.

apole · Post by **apole** » Mon Feb 04, 2008 2:02 pm

OK,

Maybe a daft question but 215/65/R15 is a much more common tyre size than 70.

Would it make more sense to put 2 of those size on the front and keep the rears at 70 or is that a daft thing to do?

Just trying to think longer term as tyres will wear out at some point.

Don't have the manual with me to check if that is an allowed size. The sticker on the car says 195/80/R15 for the fronts.

Is the speedo driven off the front or rear wheels on a 2WD, tyre size calculator says there is quite a difference between the 80 profile and what is currently on there.

Andy

scanner · Post by **scanner** » Mon Feb 04, 2008 4:43 pm

apole wrote:OK,

Maybe a daft question but 215/65/R15 is a much more common tyre size than 70.

Would it make more sense to put 2 of those size on the front and keep the rears at 70 or is that a daft thing to do?

Just trying to think longer term as tyres will wear out at some point.

Don't have the manual with me to check if that is an allowed size. The sticker on the car says 195/80/R15 for the fronts.

Is the speedo driven off the front or rear wheels on a 2WD, tyre size calculator says there is quite a difference between the 80 profile and what is currently on there.

Andy

???????????????????

The sticker on mine says 195/70 and 215/65 ...............

I'd be very surprised at 195/80.

I'd go for the 215/65 as that is the correct size for the rear and then get the same size all round as soon as possible.

I'm pretty sure the speedo drive is off the gearbox, so that's the rear axle on a 2wd and if you have 215/70s (instead of the correct 65s) on there the speedo will under read slightly as they will do less turns per mile.

apole · Post by **apole** » Mon Feb 04, 2008 4:50 pm

OK thanks,

Sticker deffo says 195/80/15 for fronts.

Checking http://www.miata.net/garage/tirecalc.html it confirms that the 80 size is as near as damn it the same as 215/70/15 in terms of diameter.

Anyway, I'll go with the 65 on both front wheels and then change the 70 on the rear when they wear down.

Thanks again.

Andy

scanner · Post by **scanner** » Mon Feb 04, 2008 5:39 pm

apole wrote:OK thanks,

Sticker deffo says 195/80/15 for fronts.

Checking http://www.miata.net/garage/tirecalc.html it confirms that the 80 size is as near as damn it the same as 215/70/15 in terms of diameter.

Anyway, I'll go with the 65 on both front wheels and then change the 70 on the rear when they wear down.

Thanks again.

Andy

What year is yours?

I was certain that everybody else has said that their stickers say 195/70 and 215/65, mine certainly does - I can't recall any mention of 195/80 at all.

apole · Post by **apole** » Mon Feb 04, 2008 6:21 pm

1999

francophile1947 · Post by **francophile1947** » Mon Feb 04, 2008 6:22 pm

Both of mine say 195/70 - I've also never heard of 195/80 tyres being recommended.

dandywarhol · Post by **dandywarhol** » Mon Feb 04, 2008 6:34 pm

I've seen 195/80 mentioned on a do0r sticker and the manual - It's used for snow tyres.
80 is the highest profile you get (used to be 82) and if a tyre has no profile indicated eg. 195/15 it is assumed to be an 80 profile.

scanner · Post by **scanner** » Mon Feb 04, 2008 7:21 pm

dandywarhol wrote:I've seen 195/80 mentioned on a do0r sticker and the manual - It's used for snow tyres.
80 is the highest profile you get (used to be 82) and if a tyre has no profile indicated eg. 195/15 it is assumed to be an 80 profile.

Ahh So (to coin a phrase), is this a winter equipment Bongo? That would explain the reference to a winter tyre.

I think it would be reasonable to stick with the "normal" tyre size of 215/65 for UK use and use them all round if you wish.