Okay I'll throw on my "I'm still trying to master offset" disclaimer. Please check my math, and call me out on anything if you think I'm off base.
Done some searches but couldn't really get answer I wanted as I have never really understood this wheel offset stuff .
If normal 14" wheels are et 11 ( is that right ? ) then what will happen with 15 x 7 with ET 7 . Will they work on standard ride height car if I don't go too wide on the tyre size .
Thanks Paul
Assuming you have 14x6 ET22 factory wheels. The diameter is irrelevant at 14" or 15". I'd say it matters at 17"+. Now assume that you are going from 14x6 ET22 factory wheels to 15x7 ET7. You are moving your wheel out 15mm, now add another 13mm for the extra half inch (on each side). Your new wheel sticks out another 28mm, just barely over an inch. As far as the inner goes, you moved your wheel out 15mm, but added 13mm in width. That means your new wheel is 2mm further away to the strut tube. Your inside situation is handled. The question is, do you have an inch clearance on the outer edge? I'm assuming so since the factory 7" wheels are ET11, and jumping to an ET7 would be adding a mere 3mm, just over 1/10th an inch.
Several have mentioned negative offsets here. Think about what you are saying about an offset of ET-11. Negative offset means the wheel hub mounting surface (not the wheel lip) is closer to the strut side of the wheel than the outer side of the wheel. Now look at a factory 6" wheel. The mounting surface is clearly biased towards the outside of the wheel, which is why factory wheels only have about 1" of lip. That is positive offset not negative. Even factory "deep dish" wheels like the BBS RC090 found on the e39 were ET20 (positive 20). The effect is accomplished by a concave wheel face. More negative offset does give you more "dish", but you won't find a negative offset BMW wheel on anything short of a CSL racecar. All BMW factory wheels have positive offset. E9's through e24's generally range from ET11 to ET 24. Later models including the E30's had offsets in the ET30+ range, forcing your inner wheel lip right into the strut tube, as the higher offset wheels move the mounting face towards the outside of the wheel.
Look at your BMW wheels. You will not find a negative number in front off your offset, because they have positive offset.
the stock 6" wheel was et-22. the 7" alpina wheel was et-11.
all 7" wheels for a coupe should be et-11, regardless of diameter.
I believe that this is incorrect. The offset numbers are correct but they are positive not negative.
Hi Paul02, its unlikely anyone who has not used a wheel with that specific offset will be able to answer your question, particularly if you are seeking to compare a 14" wheel to a 15" wheel.
Note too that you are not properly denominating the offset. et-11 indicates a negative offset of 11mm, meaning the mounting face of the wheel is further inboard as compared to the wheel centerline. Conversely, et11 indicates a wheel mounted 11mm outward from the centerline.
I believe that this is correct, although I think Paul had it right. ET11.
Comparing a et-11 to an et-7, the mounting face of the et-7 wheel would be 4mm further out in comparison to the wheel centerline. If, by chance, you were comparing two of the same wheel and tire combination with these two offsets, the et-11 wheel would appear deeper, you would have less clearance on the inside because the tire would be closer to the strut and the tire would be a little more tucked into the fender, urther away from the fender lip.[/
I believe that the first sentence is correct. ET-11 would appear deeper than ET-7. For positive offset BMW applications, ET11 would appear less deep that ET7. Your comment about being closer to the strut would be true for positive offsets. The inner lip on ET11 is closer to the strut than ET7. The inner lip on ET-11 is further from the strut that ET-7
Conversely, the et-7 wheel/tire would not be as dished, and would be more likely to contact the fender lips.
I believe that this is incorrect. ET-7 moves your wheel 3mm further away from the fender lip than ET-11. This statement would be true for ET7 versus ET11.
Negative offset truck wheel ET-46:
ET-46
BMW ET46:
Positive Offset Alpina:
A BBS RC090 amplifies the "dish" effect by using concave wheel faces.
