15" tire size

[2761377]

been running 205/60-14 sumitomo htr200's on stock basketweaves and am really satisfied with the performance and fuel economy. they are somewhat sensitive to hydroplaning, which i blame on the 'huge' contact patch and vehicle lightness.

now that i've upgraded to 15" wheels, i'm plexing on size. to retain overall diameter i can go 205/55-15 or 225/50-15. the sumitomos are not available in 205/55, and the general exclaim uhp's, which are my second choice are on 6-8 week backorder.

from experience, i would like to hear what to expect with 225/50-15 sizing. rubbing anywhere? how does that size help/hurt fuel economy? i would think such a larger contact patch would hurt fuel economy, in comparison. and, how about hydroplaning? we had very heavy rains this year in socal, and i found i couldn't exceed 65-70 for fear of skipping over the freeway like a flat rock.

photos of your car with 225/50 would be cool.

thanks,
robert w.

[1991 E30 M42]

I don't think I have any pictures but I was running 205/55r15 front and 225/50r15 rear and it looked great, it made the car look more aggressive. The problem that I had was with the fact that I have a 7" rim so the tire bulged out a tad made the sidewalls flex alot when cornering hard. As far as hydroplaning I had no issues but much of that depends on the tire, I found that a directional tire helps a lot because the tread pattern is designed to channel water away from the center of the tread.

[Eurospec]

Here are some shots of my car on 15x7 RS' and 225/50 Falken Ziex 512's, LINK. Keep in mind that falken tires in this particular size run meatier than other brands. No rubbing whatsoever and you won't have any problems in this department even on a more aggressive suspension.

Here's a buddy's (m42stephen) ride on RS' w/ aftermarket lips and I believe falken 912's-- 205 fronts and I think 225 rears. He's on coilovers btw.



I will admit, they do flex quite a bit under hard cornering and are loud as heck even though they have plenty of life left! My next set of tires will either be BFGoodrich g-force sports or Toyo T1r's in the same size... leaning towards the latter. Both will do fine in wet weather (no need to exceed speed limits in the rain anyhow).

[Warsteiner]

Robert,
Hydroplaning happens no matter what at 50+ mph. It all depends on how well the tire can channel the water and how the road is crowned. As far as a 15", the E30M3 came stock with 205/55/15 but with a 7.5" rim. I have gone to 225/15/50 on a 7.5" with no issues there and I have clocked 30mpg on an S14 motor:) Not sure what our M42's will do. I do remembering drafting my buddy and his trailer going to Watkins Glen and my M42 got 39mpg. I don't think that had anything to do with tire choice..LOL  Like everyone said, there would probably be some minor issues with a 225 on a 7" rim. Your car will handle well on 205's with no issues and to boot the tires are cheaper too. It all depends on what is available in either size to your liking. The car will handle a little bit better with the 50 aspect ratio due to it being a little bit of a stiffer sidewall but that means a harder ride too.

Good luck....

Cheers,
~Ralph

[robrez]

225/50/15 Falken Ziex 912 on 7' et25 BBS RGs. Though they are proper fitment and don't rub, I think they look a little too bulged out. I'll prolly go with 205/55 next time.

[2761377]

thanks everybody- the pics and info helped my decision- 205-55, probably kumho asx tires.

i suffered enough with staggered fitment on my wife's e28- never again. as i age, i find more value than i used to in conservative, less than 10/10ths mods. kinda makes me want to pull the h&r's and bilstein sports off my tii.

robert w.

[Eurospec]

225/50/15 Falken Ziex 912 on 7' et25 BBS RGs. Though they are proper fitment and don't rub, I think they look a little too bulged out. I'll prolly go with 205/55 next time.

Those RG's look awesome! Nagaro centers?

[robrez]

Those RG's look awesome! Nagaro centers?

Thanks, yes Nogaro Silber. I just got the caps, now I gotta paint them to match.