Ok, a little background on my car. I have a 2001 Pontiac Grand Prix GTP with the supercharged 3.8L engine. The car has an intermediate level of engine, exhaust, and PCM modifications and is used mainly as a pleasure vehicle. It comes out when I want a nice vehicle for a date, to play on the local cruising strip, or when I head to the drag strip. I have a "beater" 1990 Cavalier that serves as my winter car and my daily driver. The car sits in a heated underground garage, and if it comes out in cold weather it gets fully warmed up before being put away again. Occasionally, the Prix sees a week or two of continuous use when the Cavalier is down for repairs. There are now 28,000 miles on the odo. I bought the car new and it got its first oil change at 500 miles to Mobil 1 10W-30 with a K&N oil filter. From there, it got another two M1/K&N changes before I switched to RP 10W-30 with a K&N filter at 10,000 miles. From then on, it's been RP 10W30 and a new K&N every 5000-6000 miles. I decided that since I'm running synthetic, I'd split the difference between the old 3,000 mile guideline and 7,500+ mile "extended drains" and follow the OLM in the car. Doing that generally puts me around 6,000 miles.
What I'm looking for is the "best" oil for this engine in terms of wear/HP/mileage over the course of a 6000 mile change interval, with a new K&N filter at every change. The ability of the oil to stand up to a 10,000-12,000 mile OCI is of no concern to me since it'll never happen. If this turns out to be something in the $9.00/qt. range, so be it. Considering the ammount of toluene I go through over the summer at $9.00 a gallon for home brew race gas, I'm not about to skimp on the oil. AMSoil, Red Line, and RP are now all available locally in the Milwaukee area, so availability is not a concern. For my own reasons, I'd like it to be a "true" synthetic, i.e. PAO or Ester based oil rather than a blend, and I'm not sure I want to chase my tail trying to find German Castrol. I don't want a "race only" oil that is only good for 500 miles and won't hold up to 6000 miles of street use, but I don't need once a year oil either.
I've been tossing around the idea of switching oils and going to a street/race grade like RP Racing 21 and/or to a lower viscosity like 5W-30 or 0W-30. I do know that a number of '97-2003 Grand Prix owners have gone to lighter grades and GM now fills their 3800 series engines with 5W-30. I'm not entirely sure of the benefits/drawbacks to doing this.
I'm soliciting opinions and personal experience here, particularily from those with GM 3.8L experience. I've read a number of the "best" oil threads and everything I could find on the GM 3.8L in particular, but there is way too much information for one person to process, and I'm looking for a particular subset of the data. More to the point, I'd like to separate the concern over extended drain intervals out of the discussion. If an oil provides excellent wear numbers for 6000 miles, and significantly reduces friction, resulting in improved power and economy, but its TBN at 6000 indicates that it's just about used up and would not be suitable for a 10,000 mile OCI, that's just fine.
What I'm looking for is the "best" oil for this engine in terms of wear/HP/mileage over the course of a 6000 mile change interval, with a new K&N filter at every change. The ability of the oil to stand up to a 10,000-12,000 mile OCI is of no concern to me since it'll never happen. If this turns out to be something in the $9.00/qt. range, so be it. Considering the ammount of toluene I go through over the summer at $9.00 a gallon for home brew race gas, I'm not about to skimp on the oil. AMSoil, Red Line, and RP are now all available locally in the Milwaukee area, so availability is not a concern. For my own reasons, I'd like it to be a "true" synthetic, i.e. PAO or Ester based oil rather than a blend, and I'm not sure I want to chase my tail trying to find German Castrol. I don't want a "race only" oil that is only good for 500 miles and won't hold up to 6000 miles of street use, but I don't need once a year oil either.
I've been tossing around the idea of switching oils and going to a street/race grade like RP Racing 21 and/or to a lower viscosity like 5W-30 or 0W-30. I do know that a number of '97-2003 Grand Prix owners have gone to lighter grades and GM now fills their 3800 series engines with 5W-30. I'm not entirely sure of the benefits/drawbacks to doing this.
I'm soliciting opinions and personal experience here, particularily from those with GM 3.8L experience. I've read a number of the "best" oil threads and everything I could find on the GM 3.8L in particular, but there is way too much information for one person to process, and I'm looking for a particular subset of the data. More to the point, I'd like to separate the concern over extended drain intervals out of the discussion. If an oil provides excellent wear numbers for 6000 miles, and significantly reduces friction, resulting in improved power and economy, but its TBN at 6000 indicates that it's just about used up and would not be suitable for a 10,000 mile OCI, that's just fine.
