This from the "Tech Correspondence" section of the May, '06 issue of Road & Track:
"OIL WEIGHT QUANDARY
I've been using Redline oil in my 2002 Sabaru Imprezza WRX since its original break-in period. The air temperature where I live rarely dips below freezing. I understand 5W-30 is recommended but chose 10W-30 due to its tighter viscosity range, which should mean fewer additives and less chance of lubricant breakdown under extreme conditions. The car has 60,000 trouble-free miles including eight or ten track days. Would the lighter weight oil be better for the engine?
I suspect this is probably overkill, but both oils are offered, so there must be a difference.
Ken Levin
Point Reyes Station, California
We'd stick with the slightly heavier weight 10W-30 for just the reasons you cited. Plus, if you are track driving, the narrower viscosity range should perform better with the elevated oil temperature you're sure to get at the track, and cold-start lubrication should not suffer because you aren't subject to truly cold starts. The very thin 0W and 5W oils are relatively modern lubes aimed mainly at improving fuel economy by reducing internal engine drag."
Flail away!
(If anyone is really at odds with the response, express your reservations to:
[email protected], or
Technical Correspondence
Road & Track
1499 Monrovia Ave.
Newport Beach, CA 92663
Don't forget to include your first and last name, hometown, and state. I'm certain all correspondence will receive appropriate consideration.
)
"OIL WEIGHT QUANDARY
I've been using Redline oil in my 2002 Sabaru Imprezza WRX since its original break-in period. The air temperature where I live rarely dips below freezing. I understand 5W-30 is recommended but chose 10W-30 due to its tighter viscosity range, which should mean fewer additives and less chance of lubricant breakdown under extreme conditions. The car has 60,000 trouble-free miles including eight or ten track days. Would the lighter weight oil be better for the engine?
I suspect this is probably overkill, but both oils are offered, so there must be a difference.
Ken Levin
Point Reyes Station, California
We'd stick with the slightly heavier weight 10W-30 for just the reasons you cited. Plus, if you are track driving, the narrower viscosity range should perform better with the elevated oil temperature you're sure to get at the track, and cold-start lubrication should not suffer because you aren't subject to truly cold starts. The very thin 0W and 5W oils are relatively modern lubes aimed mainly at improving fuel economy by reducing internal engine drag."
Flail away!
(If anyone is really at odds with the response, express your reservations to:
[email protected], or
Technical Correspondence
Road & Track
1499 Monrovia Ave.
Newport Beach, CA 92663
Don't forget to include your first and last name, hometown, and state. I'm certain all correspondence will receive appropriate consideration.