Hey MrNickleye!

mrnickleye · 08-19-2006, 01:42 AM

STP is an oil additive. It been around for 40 years. I use it with each oil change to leave a film on all the parts so that when I start a cold engine, they are lubed and slippery.

The most wear on an engine is at a cold start.

Here is an interesting article on oil change intervals.
http://neptune.spacebears.com/cars/s.../interval.html

There was a thread on SM forum about 10k + mile oil changes. I totally disagree with that.

Because...after well over 1000 oil changes I've done (shop work of course), I go with the 3-5k change on regular oil.

Raw gasoline slips by the rings and dilutes the oil. There is NO stopping it. This happens more with stop & go driving (town).

Gasoline is a solvent. The gas in the oil will act as such, and deteriorate the lubrication abilities of the oil.

I've drained oil with 8-10k on it, and it was water thin, and smelled like pure gas. Just changing filters, and not the oil, as some have suggested in these forums, will not remove the gas.

If city is mostly what you drive, then even synthetic (10k intervals) will get overly diluted.

The PCV system, (which is REALLY GOOD for the engine), helps remove those fuel vapors from the oil as the car is driven. Out on the hwy works best, as the engine needs to be completely warmed up to 'vaporize' the gas in the diluted oil.

Thats why I would NEVER put those little 'kool looking' filter systems on my car's valve covers. That system relies solely on the engines blowby, and does not remove the fuel vapors from the crankcase. Those are great for looks, and car shows, but not for a daily driver.

As I stated in another thread, Slick 50 is teflon, and it was not designed for combustion engines. DuPont has a statement out proclaiming that info, and sued Slick 50 over their claims.
..............................................

My '89 owner's manual says (also on the back cover), to use fuel rated at 87 or higher (this is the # on the pump). And for improved performance to use 91 octane.

Here is a great article on this....
http://www.leeric.lsu.edu/bgbb/7/ecep/trans/b/b.htm

And yes, its true.

If mine were a stock turbo, I would run 89 winter, and 91 summer. A Modded turbo would be 91 or higher.

I use 89 in the summer because it gets well over 100*, and I run 15* timing (vs 10*). I don't want the pinging that might occur with 87, thus retarding my timing. I've noticed a 1 mpg increase with 89.

08-19-2006, 01:42 AM	#7
mrnickleye 1000whp postwhore Join Date: Jun 2005 Location: Mojave Desert, Calif. Posts: 1,705	oil & gas STP is an oil additive. It been around for 40 years. I use it with each oil change to leave a film on all the parts so that when I start a cold engine, they are lubed and slippery. The most wear on an engine is at a cold start. Here is an interesting article on oil change intervals. http://neptune.spacebears.com/cars/s.../interval.html There was a thread on SM forum about 10k + mile oil changes. I totally disagree with that. Because...after well over 1000 oil changes I've done (shop work of course), I go with the 3-5k change on regular oil. Raw gasoline slips by the rings and dilutes the oil. There is NO stopping it. This happens more with stop & go driving (town). Gasoline is a solvent. The gas in the oil will act as such, and deteriorate the lubrication abilities of the oil. I've drained oil with 8-10k on it, and it was water thin, and smelled like pure gas. Just changing filters, and not the oil, as some have suggested in these forums, will not remove the gas. If city is mostly what you drive, then even synthetic (10k intervals) will get overly diluted. The PCV system, (which is REALLY GOOD for the engine), helps remove those fuel vapors from the oil as the car is driven. Out on the hwy works best, as the engine needs to be completely warmed up to 'vaporize' the gas in the diluted oil. Thats why I would NEVER put those little 'kool looking' filter systems on my car's valve covers. That system relies solely on the engines blowby, and does not remove the fuel vapors from the crankcase. Those are great for looks, and car shows, but not for a daily driver. As I stated in another thread, Slick 50 is teflon, and it was not designed for combustion engines. DuPont has a statement out proclaiming that info, and sued Slick 50 over their claims. .............................................. My '89 owner's manual says (also on the back cover), to use fuel rated at 87 or higher (this is the # on the pump). And for improved performance to use 91 octane. Here is a great article on this.... http://www.leeric.lsu.edu/bgbb/7/ecep/trans/b/b.htm And yes, its true. If mine were a stock turbo, I would run 89 winter, and 91 summer. A Modded turbo would be 91 or higher. I use 89 in the summer because it gets well over 100, and I run 15 timing (vs 10*). I don't want the pinging that might occur with 87, thus retarding my timing. I've noticed a 1 mpg increase with 89. __________________ Had a Red 1989 N/A. Automatic. Sports Pkg. w/wing. TEMS, and some nice MODS. Sold to a friend 10/08/08.