Finally bit the bullet and replaced the tires on my Baby.

The originals lasted almost 43000 km (26875 miles) The bank account is hurting now though. $1950 CAN installed. Was the best deal I was able to find up here in Canada. Went with the Good Year F1's again.

Hoping to get some good driving time in before the snow flys and I have to put the truck away for the winter.

I was going to post a pic, now that I have a digital camera, but apparently that function is turned off...stay tuned.

 

how much is that in u.s. money?

 

Holly *****! You paid how much? $1950cdn = $1476.84 USD
Next time you buy tires let me know. I'll buy 8 tires and hand deliver yours to the fornt door and pay for the install.

 

Holy Schmoley!!! I just paid US$614 for 4 KDWs from Tirerack. Is there a surcharge for Canada? I thought NAFTA took care of that?

 

Whoa, for that kind of money, a trip into Spokane would have been worthwhile to buy them stateside. Oh well, as long as you're "Still Smiling".

 

Whats a KDW..

 

It's a BF Goodrich g-force TA KDW I assume. There are a couple different variations of this tire I think. I didn't know they made a size that would fit an 18x9.5 rim though?

 

BF Goodrich KDW2s actually. Stands for Key tech Dry and Wet. It's their 2nd gen of this tire, and is supposedly very sticky.


I drive over 100m a day highway driving, so I've been looking for something that would increase my mpg and ride quality, and still get good traction. They just came out with the KDW2 in a 285/60/18. It's 31.5", and will lower my wheel rpm @ 60 mph from 809 rpm to 646...this effectively changes my gears from 3.55s to 2.84s, or my cruising rpm of 2500rpm to 2000. My handling will suffer, but I'll buy specific wheels/tires if I decide to race.

 

I thought that for every 3 inches lost or gained in tire height equals 1 gear change. So if you had a 28 tall tire with a 3.73 gear and went to a 31. You would lose 1 gear making your overall gear a 3.55.

 

I was using the rev per mile info on Tirerack, which is wrong...they show 810 for the F1s, but the math doesn't work out. It should be 710. I guess I shouldn't have relied on derived info (but I thought everything posted on the web was true!)

28.4" x 3.14 = 89.176" covered per rotation. (Circumferance of a circle is PI x diameter.)
31.5" x 3.14 = 98.91" per rpm

63,360 inches per mile

63,360/89.176= 710.5 rotations per mile for the F1s
63,360/98.91 = 640.58 revs per mile for the KDWs.

640.58/710.5 = .9015 correction factor for gear ratio

3.55 * .9015 = 3.20 effective gear ratio.

Cruising rpm will drop from 2500 to 2250, and the speedo will be off by about 10% (Hummm, my warranty mileage will last longer too. )

 

http://www.svtlightnings.com/svt/how...calculator.htm