I drive
A drive a lot. 2005 ram 353,000 miles, 2002 Tahoe 287,000 miles, 1999 4runner 387,000 miles. I bought all three brand new. All three still pass Calif. Smog and all three pure like kittens. I have never used anything but walmart 10-30, 20-50, 5-20, even synthetic mixed with...