Came across this today and thought I'd share.  It's a coupon for $10 off of any Mobil 1 oil if you buy at least 5 quarts, or one of the 5 quart jugs.  You also have to buy it at Autozone. 

http://www.mobiloil.com/USA-English/MotorOil/Files/Mobil_1_$10_off_Coupon_at_Autozone.pdf

You might need to copy and paste the link.  It's not working correctly when I click on it from here.  I think the dollar sign is messing up the tag.

I think I'm going to use this to try out the 10W-40 4T oil in my C-14.  I have less than 1500 miles on the Rotella 5W-40 Synthetic and my shifting already feels pretty notchy.

Gearhead82, thanks for the heads up.  I'm due for a oil change in two weeks or so.

I think I'm going to use this to try out the 10W-40 4T oil in my C-14.  I have less than 1500 miles on the Rotella 5W-40 Synthetic and my shifting already feels pretty notchy.

I noticed the same thing when I used the Rotella T6 after 2,000 miles or so.  I use the Rotella 10-40 now and it shifts like butter.  And it is only $14 for a 5 quart jug to boot.