Tall Tire Question

[sildergu]

Lots of posts wondering how wide is wide, I'd like to know how tall is tall.

It's time for four new snow tires. I've installed a set of Eibach springs and shocks, the car rides quite a bit lower than stock. It's great in the summer, in the winter the car often pancakes. I've got my own little snowplow. I'd like to raise the car, if possible.

I've got a set of steel wheels just for winter. The stock tires are 205/60/15. Can I use a 205/75/15? How big can I go?

The car's a 1995 318ti Sport.

[2ndBimmer]

Going to 205/75/15 will throw off your speedo and such.

205 is an absolute size (mm), but the 60 or 75 is a %. So to keep the diameter of the wheel/tire the same, you need to alter widths and 'aspect ratios.'

205/60/15 is spec'd at 24.7". 205/75/15 is 27.1 inches in diameter.
For winter driving narrower is generally better (for cutting thru snow). 185/65/15 has a diameter of 24.5", so if you get alot of snow, you could move to tires of that size and not throw off your guages.

Since i dont get alot of snow in my area (generally, though last year was hell) i stuck with 205/60/15 (24.7 inches) for my new winter tires; for summer i went to 225/50/16's (25 inches)(got some nice wheels on ebay for ~$330).

Would a taller tire fit? I dont see a problem actually fitting the tire, but moving over and inch in diameter and you will be throwing off your speedometer and odometer.

[Travis]

I also have a '95 sport, with bavarian auto sport springs and good old blue and yellow sport shocks - Summer size: 225-45-17.

My winter tires are Blizzak WS-50's, 205-60-R15's, which perform very well for the 110 mi/day commute. I hit the secondary (tertiary, actually) roads at about 5:00 a.m. and really enjoy busting those drifts while the plows are still busy with the 4-lanes.

If you didn't already have rims, or don't care about buying another set, you could talk to the guys at tire rack about your expected winter driving to see if a narrower tire would work better for your conditions.

-Travis

[tastade]

You could probably go one size taller, but your speedo will show lower, ie if before you were showing 75 mph with an actual speed of 75 mph, it would probably show 72-73 with an actual speed of 75 mph. But normally cars show high, i.e. they show 75 when you are really going 72-73 mph.

As 2nd bimmer was saying, I would also go narrower, get like a 185 or 175 with the right aspect ratio to be 1 inch or so larger in diameter than stock. You could ask a tire place how tall of tires would fit, you don't want them rubbing while turning or when hitting bumps.

Personally I just drive my old crappy truck in the winter. You can get a good winter vehicle for not much more than the price of snow tires. I sold a 4x4 tercel for $500 with good winter tires on it (tires are only $36 each for 13 inch BF Goodrich's). Sure it did have 230k miles on it, but the tires were tall and skinny and it got about 30 mpg mixed driving. It didn't even burn a drop of oil. Even when abused those cars are good to a 200-300 thousand miles, most people were commenting that mine was still low miles, theirs had 300-500k miles. The car is overbuilt for it's 50 hp.