Been using the Royal Purple for about 2 years now. Seems to be a good oil. Noticed the dip stick went in the hole smoother after I switched. I know, thats not very scientific, but it DID feel smoother!!!
Fuel mileage stayed about the same, am changing about every 12,000 miles, replacing the filters every 2500. Engineer at Royal Purple said to run for 25 K before changing but I want to get bypass filter in first.
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Stan
93 2WD extended cab, Banks Power Pack, K&N Air Filter, PW Injectors,Auto w/4. 10 rear with limited slip, US Gear Exhaust Brake, 31/2" Exhaust, 5K air bags, Boost/Pyro/Tach Gauges, Green/Silver, new 40-20-40 bucket seats, 149K