Mismatched tyres - E60

[Antoin]

Would it cause any issues if I had 245/40/18 (standard size) on the back and 225/40/18 on the front with the abs/ traction control/ DSC etc? Due to the different rolling circumference which i believe will be out by 2.3%?

 

[quattro Rick]

Would it cause any issues if I had 245/40/18 (standard size) on the back and 225/40/18 on the front with the abs/ traction control/ DSC etc? Due to the different rolling circumference which i believe will be out by 2.3%?

Is the big traction issues not more of an X drive type issue? Wouldn't imagine there's anything to worry about if the axles are separated and have same profiles per axle but I could be wrong

 

[Antoin]

@quattro Rick its more for the sensors thinking that the wheels aren't doing what they should rather than any mechanical problems ie fronts seemingly going quicker than the rears due and it then cutting the traction control in?

 

[quattro Rick]

@quattro Rick its more for the sensors thinking that the wheels aren't doing what they should rather than any mechanical problems ie fronts seemingly going quicker than the rears due and it then cutting the traction control in?

Again I could be off, but I doubt 2% is a big enough difference, there's probably a bigger difference from a new tyre to a worn once, so it's possible they have an allowance built in.

Just turn off traction control when you get in

 

[Woodcutter]

40 profile on both, so I’m sure they’ll be fine. Can’t imagine the width difference will have any effect as the rolling circumference is the same?

 

[pablo]

40 profile = 40% of width so the sizes are different as widths are different

 

[Woodcutter]

40 profile = 40% of width so the sizes are different as widths are different

Well you learn something new every day!

 

[Antoin]

Well you learn something new every day!

And you in the motor trade and all lol

Again I could be off, but I doubt 2% is a big enough difference, there's probably a bigger difference from a new tyre to a worn once, so it's possible they have an allowance built in.

Just turn off traction control when you get in

Good point!

 

[Woodcutter]

And you in the motor trade and all lol


Good point!

Luckily we don't sell tyres! lol

Just buy the right tyres anyway you tight arse!

 

[da.murf]

40 profile = 40% of width so the sizes are different as widths are different

today I learned lol.... always had in my head the 225/45/18 was always a measurement or some type.

so on my zed the front is 225/45r18 and rears are 245/45r18

technically then the sidewalls are slightly thinner on front then.

 

[Antoin]

Luckily we don't sell tyres! lol

Just buy the right tyres anyway you tight arse!

I'm always looking a bargain lol

 

[pablo]

today I learned lol.... always had in my head the 225/45/18 was always a measurement or some type.

so on my zed the front is 225/45r18 and rears are 245/45r18

technically then the sidewalls are slightly thinner on front then.

yeah you'll often see 225/45/17 on the front and 255/40/17 on the back to even out the tyre thickness while getting a wider rear (BMWs etc)

45% of 225 = 101mm
40% of 255 = 102mm

 

[RubberLover]

Whats the sizes shown on the door placard/ tyre pressure sticker?

 

[Antoin]

Whats the sizes shown on the door placard/ tyre pressure sticker?

Il have to check when I get home

yeah you'll often see 225/45/17 on the front and 255/40/17 on the back to even out the tyre thickness while getting a wider rear (BMWs etc)

45% of 225 = 101mm
40% of 255 = 102mm

Same with the e46;
Rear 255/35/18 - 89.25mm
Front 225/40/18 - 90mm

Although I just ran 225/40/18 all round with no ill effects.

 

[pablo]

aye should be dead on, Id imagine TCS needs a lot more than 2.3% slip to trigger.

 

[dddrrift]

wont have any effect, x drive issue only

 

[Dexter mcf]

Its X3 and X5 issue (4x4) tyres need to correct size and star rated.

 

[svensktoppen]

Would it cause any issues if I had 245/40/18 (standard size) on the back and 225/40/18 on the front with the abs/ traction control/ DSC etc? Due to the different rolling circumference which i believe will be out by 2.3%?

Just out of interest, why do this? And not just sick to the sizes it's designed for?

 

[Antoin]

Just out of interest, why do this? And not just sick to the sizes it's designed for?

Seen a cheap second hand set of winter tyres in that size.

In the end I held out and found a set in the correct size.