Sorry if this has been covered before. All the threads I could find were for the 15" wheels. (Must be a lot of SE owners with non-original wheels out there!).
I just purchased this 85 GS and the prior owner had endowed the 13" wheels with lovely all-season 185-70-13 tires. I think they're T-rated
Anyway, can I go up to 205 on the original 13" wheels or is 195 the width limit? No guesses, please!
...or somebody let me know where I can pick up my 15" meshies. A set comes with club registration, right?

 

i've seen plus wheels with 215's.
searching would be good as this has been covered a lot.

 

I couldn't think of a good answer, so I spent 20 seconds at tirerack.com and got this.

235/45VR13
http://www.tirerack.com/tires/Sizes....um=345VR3EV700

 

Tom, I know quite a few people that have successfully put 205's on the 5.5" wide stock aluminum 13's. In some instances people have even gone up to a 215, but I think in some cases that the handling actually suffers after doing this because you get more sidewall flex in the tires. People usually think that the widest tire possible is the optimum choice, but that's not always the case. Your best bet is probably a 195 or a 205.

 

I have run Sumitomo 205/60/13 and 215/50/13 both without any issues. I'm currently running the 215s and they do fine for daily driving and autocrosses (of course not as good as real race rubber though)... This is using the stock "plus" wheels on my '85 GS...

 

i have 215/50/13's ready for stock meshies

 

13in stock meshies??

 

Going by the aspect ratio, the stock 185/70 tires have a sidewall height of 129.5mm. that would put the 215/50 tires at 107.5 mm sidewall height. That's a pretty big difference, no? If our speedos are calibrated for the rolling diameter of a 185/70 tire, then we probably think we're going faster than we are when we're wearing 215/50 tires on the rears. Lower gas mileage and lower top speed in each gear too. Better cornering (shorter sidewall height, less flex) and grip though, for sure. Am I all wet on this one?

 

No, I think you have it right. The 195/60 come closest to the stock tire diameter but the 205 offer a bit more width and only sacrifice a small difference. I agree the 215 are way out of the spec and will have very noticable speedo errors.

I run 205/60 on the stock waffles and have for at least 15 years. Its the best size but now its very hard to find. I may go to 195 so I can get a better choice of tires. Sumitomo is it for 205/60 at the moment.

 

I picked a pair of good used 205/70 R13's for about $40 that I have on the rear and I think it's just fine.

 

I found 205's in the front made the steering just a little too heavy for my liking. But 195's were fine. I kept the 205's in the rear though.

 

yeah. well mine are painted gold for the LS so that makes them more awesome!