New Rims? what's the deal?

[cavekidd]

Front : 35offset 18" x 8.5
rear: 40offset 18" x 9.5
BBS RS


I am trying to buy a set off BBS RSs ^^ as stated, but can someone tell me what the big deal is about having such wheels on an awd car? I am not that inclined in terms of wheels to know that a 8.5-9.5 stretch is apparently bad for and awd? This is what I am hearing from my friends.
Can someone please elaborate and tell me if I'm making a good or bad choice.
Really like the bbs rs on b5s but apparently stretching your tire or having such wide rims initially is a bad thing for an AWD.
"You will break an axle" ??

Lol enlighten me, guys.

[Rodgman15]

Pretty sure offset in width doesn't make much if any difference. The thing you need to keep a close eye on is maintaining the same ( +/- 3% ) rolling diameter at all four corners, that'll mess shit up if you get out of those tolerances.

I'm no expert by any means, but that's what I've gathered.

[ray4624]

^^what he said

[mjfloyd1]

If you use the same size tires it is no problem. It is also no problem if the diameter of all 4 tires is within 3% as the other poster said. Larger (wider) rear tires create understeer IIRC.

[crazyquik22023]

I have to disagree. While having different sized tires might have some effect on steering (probably only would be noticeable if you were using the car for track events or such) as said above, having wider wheels in the rear really does not put any extra stress on drivetrain parts. Some people say it will ruin your differential, axles, etc. But from my experience this is not true, especially if you get BBS RS's since they are aluminum and will have almost no weight difference. The stretch you are talking about is when people stretch tires on their wheels so the sidewall can clear for very low cars. Stretching tires is something you should avoid if you are using your car for track/race events or such things. It really depends on what you are going for with the car. Here is my current b5 with 9.5's in the rear and 8.5's in the front. 205/35/18 tires in the front, 205/40/18 tires in the rear. No problems at all for years.

[Kronprinz]

^205/35/18 feels like running over a speed bump when you run over mouse droppings.

[rodgertherabit]

Interesting to hear! crazyquik22023 ...

any factual data to back it up? not saying your mistaken or anything... just sounds like good news to me! ;-)

[Sumo337]

I was running 8.5/9.5 205/45/17s squared on my TH-lines.



Now, I'm running 18x9.5 215/40/18 squared on my WCI MT10s.

[Kronprinz]

I have to disagree. While having different sized tires might have some effect on steering (probably only would be noticeable if you were using the car for track events or such) as said above, having wider wheels in the rear really does not put any extra stress on drivetrain parts. Some people say it will ruin your differential, axles, etc. But from my experience this is not true, especially if you get BBS RS's since they are aluminum and will have almost no weight difference. The stretch you are talking about is when people stretch tires on their wheels so the sidewall can clear for very low cars. Stretching tires is something you should avoid if you are using your car for track/race events or such things. It really depends on what you are going for with the car. Here is my current b5 with 9.5's in the rear and 8.5's in the front. 205/35/18 tires in the front, 205/40/18 tires in the rear. No problems at all for years.

It is not the tire width that can run your diff, if the rolling diameter. You can put 15" wide on one axle and 3" wide on another with no ill effects as long as the rolling diameter is within 3%

[crazyquik22023]

Interesting to hear! crazyquik22023 ...

any factual data to back it up? not saying your mistaken or anything... just sounds like good news to me! ;-)

Haha no data besides the fact that I have been running them for years. And i mistyped in my last post. My tires are 215/35/18 in the front and 215/40/18 in the rear. Not 205's.

It is not the tire width that can run your diff, if the rolling diameter. You can put 15" wide on one axle and 3" wide on another with no ill effects as long as the rolling diameter is within 3%

I never said anything about the tire width ruining your diff.

[cavekidd]

Pretty sure offset in width doesn't make much if any difference. The thing you need to keep a close eye on is maintaining the same ( +/- 3% ) rolling diameter at all four corners, that'll mess shit up if you get out of those tolerances.

I'm no expert by any means, but that's what I've gathered.

Yes, this is exactly what I have been hearing as well.
But I do not know how to go about it if I were to buy those rims. 18 x 8.5 & 18 x 9.5 what kind of tire sizes should I put on them? Elaborate on the whole +/- 3% ordeal and rolling diameter.
Sorry for my lack of knowledge lol.

[cavekidd]

I have to disagree. While having different sized tires might have some effect on steering (probably only would be noticeable if you were using the car for track events or such) as said above, having wider wheels in the rear really does not put any extra stress on drivetrain parts. Some people say it will ruin your differential, axles, etc. But from my experience this is not true, especially if you get BBS RS's since they are aluminum and will have almost no weight difference. The stretch you are talking about is when people stretch tires on their wheels so the sidewall can clear for very low cars. Stretching tires is something you should avoid if you are using your car for track/race events or such things. It really depends on what you are going for with the car. Here is my current b5 with 9.5's in the rear and 8.5's in the front. 205/35/18 tires in the front, 205/40/18 tires in the rear. No problems at all for years.

Looks beautiful.

I am not looking to use the car for track but I do like drifting in the streets of Toronto lol, although 90% of the time i'd just be cruising cool.

My question to you all is how I achieve the rolling diameter/3% similarities.

Nice car again.

[cavekidd]

I was running 8.5/9.5 205/45/17s squared on my TH-lines.



Now, I'm running 18x9.5 215/40/18 squared on my WCI MT10s.

Looks amazing man, that fitment, that lip, lool.
Nice front bumper lip too!

[Kronprinz]

cavekidd, you use 215/40/18's all around

[tar]

Assuming reps since you said rims and not wheels

[cavekidd]

Assuming reps since you said rims and not wheels

Yea this idiot selling me the bbs' s is not telling me which kind of reps they are but there is another person selling ems reps for a bit cheaper but thats cause they got a little curb rash and dings.

[cavekidd]

cavekidd, you use 215/40/18's all around

Hey, so if I went 225/40/18 on all 4 rims it shouldn't effect anything? Should I put spacers?

[OverSpun]

Yea this idiot selling me the bbs' s is not telling me which kind of reps they are but there is another person selling ems reps for a bit cheaper but thats cause they got a little curb rash and dings.

Good luck with fake BBS...

[Sumo337]

Looks amazing man, that fitment, that lip, lool.
Nice front bumper lip too!

Thanks!

[bhusted]

I really don't want to weigh in on the whole stretched tire thing, but I will comment on the circumference of the tire problem. Since all wheels are being driven, ideally they should all have identical diameters so that they all travel the same distance per revolution. Yes, there is some tolerance for minor variations, but I'm not sure who came up with the whole 3% thing. Think about this: if the rear tires are a greater circumference than the fronts, for every revolution, they will be traveling a greater distance than the front tires. You can try this out by marking a chalk line on the front and rear tires where they meet the ground. Drive in a straight line for a bit and stop to see if all of the marks still line up with each other.

In the spec sheets for each tire, TireRack lists the number of revolutions per mile. If I were going to buy different sized tires because of the different width wheels, I would be looking for a size that matched the number of revolutions per mile as closely as possible. Just my $0.02.

[cavekidd]

good luck with fake bbs...

looooooool :( :( :(

[cavekidd]

I really don't want to weigh in on the whole stretched tire thing, but I will comment on the circumference of the tire problem. Since all wheels are being driven, ideally they should all have identical diameters so that they all travel the same distance per revolution. Yes, there is some tolerance for minor variations, but I'm not sure who came up with the whole 3% thing. Think about this: if the rear tires are a greater circumference than the fronts, for every revolution, they will be traveling a greater distance than the front tires. You can try this out by marking a chalk line on the front and rear tires where they meet the ground. Drive in a straight line for a bit and stop to see if all of the marks still line up with each other.

In the spec sheets for each tire, TireRack lists the number of revolutions per mile. If I were going to buy different sized tires because of the different width wheels, I would be looking for a size that matched the number of revolutions per mile as closely as possible. Just my $0.02.

Really appreciate your input, highlighted the problem at hand, I understand what youre saying. So as long as they are all (for ex:) 225 40 18 all 4 tires no matter the rim width or 235 45 18 all 4 tired no matter the rim width, it should be good

[crazyquik22023]

Looks beautiful.

Nice car again.

Thank you

cavekidd, you use 215/40/18's all around

If he uses 215/40/18's on the front and rear then the rear tires will be a lot more stretched than the front's since he is using a 8.5" wheel in the front and a 9.5" wheel. This is not a problem, I am just stating..

I really don't want to weigh in on the whole stretched tire thing, but I will comment on the circumference of the tire problem. Since all wheels are being driven, ideally they should all have identical diameters so that they all travel the same distance per revolution. Yes, there is some tolerance for minor variations, but I'm not sure who came up with the whole 3% thing. Think about this: if the rear tires are a greater circumference than the fronts, for every revolution, they will be traveling a greater distance than the front tires. You can try this out by marking a chalk line on the front and rear tires where they meet the ground. Drive in a straight line for a bit and stop to see if all of the marks still line up with each other.

In the spec sheets for each tire, TireRack lists the number of revolutions per mile. If I were going to buy different sized tires because of the different width wheels, I would be looking for a size that matched the number of revolutions per mile as closely as possible. Just my $0.02.

I have never heard of this 3% rule either. OP stretched tires are by no means the "correct" way to install a tire on any wheel, it is mainly for fitment and I suppose the look of it for some people. If you look at the tire specs like bhusted mentioned you can find a car such as a RWD Mercedes or a BMW M3 or something similar which has from factory a wider 9.5" wheel in the rear and a smaller 8.5" in the front and see the recommended OEM tire sizes for that car.