Saturday, August 30, 2008

Extended oil change intervals and Lexus maintenance

For the last 100,000 miles on my 2000 Lexus GS400, I've been changing the Mobil 1 synthetic oil every 200 hours of engine run time. The Lexus has an engine clock which can be reset to zero, which I do when I change the oil.
For my typical driving, the Lexus computer computes about a 38 MPH average since the last reset, so that works out to about 200hrs x 38MPH = 7600 miles between oil changes.
Even thought the car is at 180,000 miles, the car burns ZERO oil, and the oil looks just a little darker at 7500 miles. The magnetic plug has no metallic sludge on it, either.
Here's a severe road test by a municipality on it's fleet vehicles, going 20,000 miles between synthetic oil changes (q10k oil filter changes) compared to non-synthetic "dinosaur' oil every 3,000 miles. The verdict? Synthetic 20K miles changes showed LESS WEAR on rod and main bearings!
Even General Motors goes a minimum 10,000 on oil synthetic oil changes with computer monitoring of the oil life.
It you 'feel' you need to change it more often, then that's not science... that's emotional decision-making. I'm trying to stick to science here. Kind of like how you would 'feel' eating worms is "yukky" and you wouldn't do it ever, but it would make perfect biological sense that worms would keep your body fed with nutrients....
Longer oil intervals = less money spent needlessly, and more Saturdays to do other projects besides changin oil.

After the driving vacation, it'll be time for the second 90K timing belt/water pump/plugs/tranny fluid/diff oil/brake fluid/power steering fluid change. There is a little "shimmy" at around 75mph, so will check the ball joints, too.

Just got new tires, rear 12 months ago, last month for the fronts. Sweet tires: Yokohama Avid V4S ... quiet, smooth, long-wearing and great grip. Use