Date: Mon, 7 May 2001 14:04:43 -0400 From: "Fadeev, Alex" Subject: RE: Tire size on '90 325ic Larry Schwarcz [mailto:lrs@cup.hp.com] wrote: > > Well, it's time for me to buy some new front tires for my '90 325ic. > But, I've now been told by two different BMW places that I should > stick to the OEM size (195/65R14). I now have 205/60R14s on the > rear since Yokahama didn't have the AVS Int in my size (yes, I really > like those AVS Intermediates!). Larry, 205/60 is what's known as a +0 upgrade over stock 195/65 tires. It's a perfectly safe and reasonable move, particularly since AVSi's are available only in 205/60 size. > Any thoughts on running a size that's not the OEM size? I have a > program that shows differences between tires sizes that says: > > Specification Sidewall Radius Circumference Revs/Mile Difference > 195/65-14 127mm 305mm 1914mm 841 0.0% > 205/60-14 123mm 301mm 1890mm 852 -1.2% > > This shows that there wouldn't be much speedo error (-1.2%) and the > new tire is 8mm (0.31") shorter and 10mm wider (0.39"). Other than your speedometer indicating slightly (1.2%) higher than actual speed, there are no negatives to going with 205/60/14 tires. Since BMW only guarantees it's speedometers to display 0-10% higher than actual speed, you would effectively we moving that margin of error window to 1.2%-11.2% over actual. > So, it seems to me that the differences are very small in terms of > how the car would handle. But, are BMWs more sensitive to tire size > differences than other makes? Nope. I wore off two sets of 205/60 AVSi's on my E30 before retiring the car into daily driver duty (SH30's from now on). AVSi's are the best dry non-R tires you can put on stock E30 wheels! alex f