urgent tyre size question.

[E34 Touring]

hi all,

sorry to drivel on about this but I have the chance to pick up a set of good quality part worn tyres for my e34 520i - I just upgraded to 18" wheels so am broke, but need tyres

they are 225/40/18 - Y rated, Continental SportContact2

Would these tyres work ok on my E34 520i touring or are they too low profile?

many thanks
Steve

[Zeuk in Oz]

hi all,

sorry to drivel on about this but I have the chance to pick up a set of good quality part worn tyres for my e34 520i - I just upgraded to 18" wheels so am broke, but need tyres

they are 225/40/18 - Y rated, Continental SportContact2

Would these tyres work ok on my E34 520i touring or are they too low profile?

many thanks
Steve
Cannot say if the tyres will fit on the rim or under the mudguards, but the diameter of the wheel/tyre combination will be smaller than stock so your speedo will be out.

A 225/60 x 15 wheel has a radius of approx 325.5 mm and your combination would work out to approx 318.6 mm. In other words the diameter of the wheel and tyre combo would be just over half an inch too small.

235/40 x 18 tyres and wheels would have a radius of approx 322.6 mm.

245/40 x 18 tyres and wheels would have a radius of approx 326.6 mm

What also has to be considered is how wide the wheels are and what the recommended tyre width range for that width of wheel is !

More info required please.

Edit : the other stock combo is 205/65 x 15 which has a radius of approx 323.7 mm.

[DueyT]

They're close....orig 225/60-15 is 78.7" circumference, 225/40-18 is 80.5"...you'll be 2.1% smaller so speedo will over-read (i.e. 60 mph actual will show as 61.3mph.)

If your 18" rims have the same offset as the original (20mm, I think?) then you should be okay.

I have SportContact2's [235/45-17(f), 255/40-17(r)] and love them!

Cheers,
Duey