Winter Tyres

missile

Hi,
I am considering winter tyre for my Q5 SLine. My car is currently shod with Michelin 235/55 R19
Audi recommend Dunlop SP Winter Sport 3D AO size 235/65 R17 104H on 7Jx17 ET37 rims. I have no doubt these would do the job, but 17 inch rims

I wonder if those recommended for the Audi A6 i.e. Dunlop SP Winter Sport 3D AO size 225/50 R18 99H XL on 7,5x18 ET37 would be suitable?

sunshinetours

I go to 17's on my 5 series in winter from 19's (they look fine). Tyres will be cheaper as well generally as well as working better in real winter conditions.

Depends on what you want I guess

Weird_Nev

Stick with Audis Recommendations.
A big part of how winter tyres work is by using the sidewall flex to open up the 'sipes' in the tread and really bite the road/snow/slush. Low profile tyres are too inflexible to do this effectively.
The smaller size will be more effective and cheaper, and actually do the job you want them for.
You'll just have to accept that an S5 on 17's looks cooler than an S5 on 19's with one wheel ripped off over a curb.

Just check that the 17's clear your calipers properly! I'd be getting audi to fit/check them to avoid costly errors.

scheming_gypsy

sunshinetours wrote: »

I go to 17's on my 5 series in winter from 19's (they look fine). Tyres will be cheaper as well generally as well as working better in real winter conditions.

Depends on what you want I guess

Weird_Nev wrote: »

Stick with Audis Recommendations.
A big part of how winter tyres work is by using the sidewall flex to open up the 'sipes' in the tread and really bite the road/snow/slush. Low profile tyres are too inflexible to do this effectively.
The smaller size will be more effective and cheaper, and actually do the job you want them for.
You'll just have to accept that an S5 on 17's looks cooler than an S5 on 19's with one wheel ripped off over a curb.

Just check that the 17's clear your calipers properly! I'd be getting audi to fit/check them to avoid costly errors.

They weren't asking if they should go down to 17's they were asking if....

missile wrote: »

I wonder if those recommended for the Audi A6 i.e. Dunlop SP Winter Sport 3D AO size 225/50 R18 99H XL on 7,5x18 ET37 would be suitable?

the same tyres on a different Audi but in the correct size, would be ok on theirs.




but it just sounds as though Audi recommend Dunlop SP Winter 3D AO tyres.. So they should be fine.

Weird_Nev

Except they may rub on arches, not fit correctly....

I think (but could be wrong) that the OP disliked the fact that 17's might compromise the look of his car. We were just commenting that fitting low profile tyres NOT recommended by Audi for his make/model might compromise the point of fitting winter tyres in the first place!

scheming_gypsy

I took it to mean that he's seen what's recommended but the recommendation is for 17 inch alloys whereas he has 19's and just wants to replace the rubber, rather than buy a new set of alloys to see him through winter..

ie - Audi recommend these but they're 17inch. I've got 19inch and they recommend these 19inch tyres but for a different car.

redped

scheming_gypsy wrote: »

I took it to mean that he's seen what's recommended but the recommendation is for 17 inch alloys whereas he has 19's and just wants to replace the rubber, rather than buy a new set of alloys to see him through winter..

ie - Audi recommend these but they're 17inch. I've got 19inch and they recommend these 19inch tyres but for a different car.

Except the OP actually said he has 19s, and is wondering if 18s would be okay ...

missile wrote: »

My car is currently shod with Michelin 235/55 R19

I wonder if those recommended for the Audi A6 i.e. Dunlop SP Winter Sport 3D AO size 225/50 R18 99H XL on 7,5x18 ET37 would be suitable?

So either way he'll be needing to get a new set of alloys (17" or 18") for the winter tyres. If he's buying new alloys & winter tyres, I'd go for the 17" ones Audi recommend for his car - that way, there'll be no issues with them fitting okay.

missile

Many thanks for your comments

missile

It is purely vanity. They will be on the car 3/4 months and the design of the 18" A6 wheels looks so much better than the 17" Q5 wheels.

It has 19" wheels on at present so I know the diameter is not an issue.

I believe ET37 is the designation for stud PCD and wheel offset. I was hoping one of you experts would be able to confirm?:A

System

Go with the size that Audi recommend.

This webpage shows the specification of the Dunlop Winter tyre (Note the overall diameter) : http://www.dunloptires.com/dunlop/display_tire.jsp?prodline=SP+Winter+Sport+3D&mrktarea=Winter&treadwidth=235&aspectratio=65&rimdiameter=17&sidewall=BSW&prodID=26502466700000&zipCode=

This Wikipedia page shows how tyre sizes can be calulated : http://en.wikipedia.org/wiki/Tire_code

Using the formula from the Wikipedia page to calulate the overall diameter of the wheel / tyre combination ....

Normal tyre : (235*55/1270)+ 19 = 29.18 inches

Winter tyre : (235*65/1270)+ 17 = 29.03 inches

So I assume the difference in diameter is within the allowed tolerance for the vehicle.

Also:
Contact your insurance company to check if they need to be informed when you change tyres from Summer to Winter then back to Summer again, they should not need to know IMO.

molerat

The 18 tyre size is way out, the correct tyre would be 235/60/18 to keep the speedo correct and is actually closer to original than the 17's

No calculations needed http://www.1010tires.com/TireSizeCalculator.asp?action=submit