Bluezone
Tailgaters will be prosecuted.
Hi guys.
I've been reading up on the focus RS all wheel drive system. Kind of interesting how it works compared to what's on the EcoBoost models of the Taurus and MKS. For learning about it one of the interesting facets besides the locking spool in the rear was that the final gear ratio between the front and rear had a differential of about 2% (they turn 2% faster in the rear). Well I recently put brand new snow tires on my 2010 MKS.
One of the things I noticed with the new tires was a tendency to be affected by road crowning at highway speed. So I decided to measure the od's of all the new tires. Surprise surprise, I had big and Littles on each axle. The tires heading outside diameter of 230 and 240 cm. This gives a differential of roughly 4%. So I'm mounted the larger diametertires in the rear and the smaller diameter tires in the front. As expected with traction control on the power cut came in sooner. But with traction control off it became much easier to power oversteer.
Mind you this is seat of the pants opinion and nothing empirical by measurement.
Has anyone else tried staggering tire diameter to see what happens?
I've been reading up on the focus RS all wheel drive system. Kind of interesting how it works compared to what's on the EcoBoost models of the Taurus and MKS. For learning about it one of the interesting facets besides the locking spool in the rear was that the final gear ratio between the front and rear had a differential of about 2% (they turn 2% faster in the rear). Well I recently put brand new snow tires on my 2010 MKS.
One of the things I noticed with the new tires was a tendency to be affected by road crowning at highway speed. So I decided to measure the od's of all the new tires. Surprise surprise, I had big and Littles on each axle. The tires heading outside diameter of 230 and 240 cm. This gives a differential of roughly 4%. So I'm mounted the larger diametertires in the rear and the smaller diameter tires in the front. As expected with traction control on the power cut came in sooner. But with traction control off it became much easier to power oversteer.
Mind you this is seat of the pants opinion and nothing empirical by measurement.
Has anyone else tried staggering tire diameter to see what happens?
), so if you're running a worn set and have a blow-out, you either need all new tires or to get one new one and have it shaved to match. I'd look up the FoMoCo tread spec for your MKS, you may have a great case to go back to the dealer for "matching" tires. Unless of course you've found a place warm enough to burn off the rears to get them to match! 
