The 166M rims look awesome without a doubt. Stick to the 275 max and you will be happy regardless.

 

Based on all my research I can say for sure the 166 rims work with 245/35-19 and 275/30-19 -- the official sizes. You can also use 285/30-19 in the rear if the 275's fit with no problem IMO. Some folks mentioned the sidwall might be different, as in larger, but according to the calculator I used it's 3.4" of tire both front and rear so its the same.

So now we know the 166 rims will fit OK and those tire sizes "officially" work.. how about doing 255/35-19 in the front and 295/30-19 in the rear? They raise the car height by 0.3" but fill in the wheel wells more.

For those curious about the tire differences:

Front:
Rear:
Based on this information I think 245/35-19 front and 285/30-19 rear is an even better fit than the 275 in the rear which is officially recommended. I'd like the even wider 255f/295r but I think I don't want to push it to the extremes.

I'm probably going to go with 245/35-19 front and 285/30-19 rear --both of which are available from Michelin. I can also drop those 10mm spacers I have in the front now to the rear to even them out with the fronts and it'll all be well! I've got a dealer service appointment tommorrow so I'll ask them what they think too. Now to goo look at pricing.. expecting somewhere around $3000...

 

I went through the same painstaking process. I was more concerned with the look, ride and rub issues when going to the 166's.

I fit the 285/35's in the back with no rub issues. From a look standpoint, this tire is perfect as it fills up the rear wheel well. The offset of the back rim is designed for this tire combination on the e60. I think the 285 fills up the wheel well better but your speedo will be off by about 5%. I think the 275 is ok and no changes to the speedo, but the wheel still looks small for the car.

The front is the problem. The 166 has a really aggresive offset for the M5 fender. I think this rim, independent of the tire, sticks out too far. The rim is .5" wider than the style 124 with a 12mm offset as compared to 20mm. It does not do much for the staggered look. I fit a 245/40 to match the sidewall ratio between the back and the front and to fill up the well, but I did have a slight rub at full suspension compression. I had one swell on the highway to my office that when I hit it at 80mph, I would hear the rub. No other times, though. The fender is already rolled so there was not option there.

To be safe, you really need to go wtih something like a 245/35 which is the same overall diameter. You can also fit a 255 on these rims, but since the offset is already pretty far out, I would not recommend from a looks standpoint.

I like the look of the 245/40 as it fills up the wheel well and looks balanced with the back. I ended up milling off almost 2mm from the rim which inset it enough from a looks standpoint and got rid of my rub issue. I believe it is safe from a structural standpoint and my research - but I can not gaurantee.

Here are the pics with 285/35 and 245/40's: http://forums.e60.net/index.php?showtopic=19370&hl=166

I have not posted pics since I have modified my offset. I will take pictures next weekend. If you have any questions, PM me.

 

I saw your post in my searching and it it's what got me thinking about filling the wheel well and about the gap. It's interesting how you went with 245/40 and 285/35 instead of 245/35 and 285/30. Didn't your entire car get raised by half an inch by not downsizing the aspect ratio to make up for the larger 19" rim? I can see the rubbing problem since your combination is a full 1" greater in diameter than the original wheels. Your tires certaintly do fill the wheel wells perfectly and it really doesnt look like the car has been raised at all. That large speedo difference would be of a concern to me though. I also don't think the front rim sticks out too far.. its just right for me. The rear rim is stuck in too far if anything. Hrmm....

 

Also, the spacers subtract from the offset (basically the smaller the offset, the farther outward the rim. You where actually the person who started me thinking that I was not happy with the wheel setup after you put spacers on your 124's - which looked good. Thanks. That cost me $3k. I was just about to order spacers when I saw pics of the 166's.

The only thing you have to remember is that the 166 is 1/2" wider in the front. So thats another 6mm into the equation - I believe. So for approximately the same position of the 124 rim, with your 10mm spacers, as the 166 rim, you would have to have about a 16mm offset on the 166 rim. After I milled my rims, I am at about a 14mm offset.

 

so have you switched to 166? which tire combination have you gone for?

cheers rumman

 

I will probably do it after the winter/snow/messy weather ends, sometime in the Spring. I'll use 245/35-19 for the front and 285/30-19 for the rear. Dealer wouldn't replace my dunlops because "rear tires are evenly worn down to tread indicator and front tires chopped up after only 6,000 miles" -- blamed me on agressive driving. I had around 10,000 miles on the first set of tires which they replaced with no question.. driving all the same. Oh well... I'll get the new rims and tires in a few months.

PS. No MP3, said I needed a new CCC unit.