I'm interested in buying a set of 16x7 Motegi MR7's for my '88 SE. On their website (motegiracing.com) the spec for that wheel says:
16x7, 4x100, 4.5, +42. I don't understand what the 4x100 and the +42 mean. The offset for that wheel is 35mm. There is no further info on their site. Any help would be appreciated. Thanks.

 

16" is the rim size
7" is the rim width

4x100 means it's for cars with 4 lug pattern
5x100 would be 5 lug pattern

4x114.3 means the thread is larger than 100 thread

there are combo wheels with 8 holes and 10 holes to accept either 100 or 114.3 threads. This wheel your're looking at may be one of them.

42 is the offset. I'm not sure where you got 35 from.

From what I can find the 88 SE's (your car) are 4 bolt 114.3. So you either need a 4 hole 114.3, or an 8 hole combo 100/114.3.

38 is a good offset if you can find it.
215 will be a good tire width for a 16" rim

 

If you have an NA then 205 is fine, you'll find that a tire and wheel combo is generally cheaper and most of the time come with a 205/40/r16 size tire.

 

First 114.3 doesn't have anything to do with threads. That's the bolt circle measurement. The wheel is a dual pattern wheel. The 4-bolt wheel is 4 x 100 and 4 x 114.3 (4 x 4.5). The 5-bolt is 5 x 100 and 5 x 114.3. Mr. E got it mostly right but his nomenclature is off a bit.

The offset is +42. It's hard to compare that number to stock because this wheel is now a half inch wider and thus will have a different offset for a simlar backspacing. At any rate, I've used this wheel and it will work well with all 215s and you can squeeze SOME 225s on it. Different tires will have slightly different true measurements for the same label. So I would stick with the 215s.

Chris