Which Wheels Are Compatible With My 2012 200D ?

[jumbojake]

Please forgive a stupid question....

Anyway, after all of the winter tyres chat, I've decided I should invest in a set of old wheels, and some new winter tyres.

Question is, what wheels are compatible?

Currently, my 200D has staggered wheels 17" 225/45 on the front and 245/45 on the rear.

I can see lots of 16" lexus IS wheels on eBay ... all 5 stud wheels...... question is, can I use them ?

(obviously I'll need a different aspect ratio to maintain the same circumference!)

any know?

[johnatg]

Yes - in a word! You can use any wheels with the correct offset (and that doesn't matter too much, within limits), correct PCD of the bolt holes (that does matter!) and correct centre bore (and bigger ones can be reduced with adapters). Any wheel originally used on any IS will be OK.

But you must choose tyres which give you more or less the same circumference as the originals - there are various tyre size calculators online to help you do that. Your tyre pressure guide on the door jamb probably lists the correct tyre sizes for different diameter wheels. Certainly the handbook does.

[jumbojake]

Thanks Johnatg - so the remaining question is what size do I choose ... My 200d has bigger wheels on the back.

I assume the rear wheels rive the spedo - so do I match those or should I try to maintain the different sizes?

[ColinBarber]

I believe the standard 16" size is 205/55/16 for all 4 wheels.

[johnatg]

IS 17" wheels with bigger tyres on the back (not sure where this term 'staggered' came from - the tyres are just wider, not the wheels) are the same width front/rear. (8JJ). (This is Type B wheel spec)

Type A wheel spec (16" wheels) are 16 x 7JJ - ie they are 1" narrower than the 17" - 205/55/16 tyres are correct on them.

(Note however - the 18" wheels fitted as options (Type C wheel spec) are different - the front 18" wheels are 18 x 8J and the rears are 18 x 8½J)

[Captain Fizz]

I believe the standard 16" size is 205/55/16 for all 4 wheels.

This is what I'm using for Winter tyres.

Using Lexus alloys. 7J and 45 offset on each.

[jumbojake]

Thanks for all the feedback.... useful stuff and lines up with what I've found elsewhere.

So, if I want to match-up the same size outer diameter, I could get 16" wheels, but different sized tyres?

Front - 225/45/17 = 634mm ~ 205/55/16 (<1% difference)

Back - 245/45/17 = 652mm = 205/60/16 (exactly the same)

Or should I just get the larger 205/60/16 all round?

any thoughts? (has anyone made this change on the 200d with 'type B' wheels?

[ColinBarber]

205/55/16 all round.

[Captain Fizz]

205/55/16 all round.

My 220D has the same summer tyres as yours John, using the 205/55's all round for winter

[ColinBarber]

John your concern seems to be related to the different circumferences between the front and back. The ECU is very likely to have been calibrated using the standard 16" wheels and so it is your summer tyres that are less accurate, or calibrated in-between so all sizes are a little out one way or the other. There isn't a different calibration between the different trim grades to compensate for the different wheel sizes.

Just your tyres wearing tread down from 8mm to 2mm introduces a 1% difference in itself, you are never going to be totally accurate.

[jumbojake]

Thanks for your replies... that's the re-assurance I was hoping for.... decision is made for my winter set-up!

As for the summer set-up.... I can't think why they chose to have these bigger tyres on the back only on the 200d... not sure why this engine is any more 'tail happy' than the others.... I guess don't need to worry about that until March!

[johnatg]

It's not just the 200D - on 17" wheels 225 front and 245 rear are standard - and 18" wheels have wider tyres on the back, too - applies to all IS range.

Someone at Lexus (marketing dept?) obviously thought it was a good idea. Probably more to do with fashion than technology - it's common on BMW and Mercedes too.

The tech bit is all to do with putting the power down on the road with rwd - but 245s are a bit overkill with 200bhp, to say the least! :eerrrmm:

[Captain Fizz]

On dry roads, on roundabouts, even in the 175BHP 220d it can still kick the back end out a bit.

Not that I would know ofc...

[ColinBarber]

Someone at Lexus (marketing dept?) obviously thought it was a good idea. Probably more to do with fashion than technology - it's common on BMW and Mercedes too.

What I don't understand is why the profile wasn't changed. Rather than having a 3% error using 245/45 they should have used 245/40 for only a 1% error. At least they got it right with the current generation of IS

[johnatg]

Indeed so - I used to have a Mercedes C-Class which had 225/45/17 at the front and 245/40/17 rear. Might try that on my Lexus next time! (Maybe some useful reduced sidewall flex and slight cost saving!)