Best oil for GM 3.8L?

Messages
12
Location
New Berlin, WI
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.
 
Messages
9,448
Location
USA
My 3.8 likes a good 40Wt. oil over a 30Wt. I am well aware that 10W30 does just fine in the engine as fell. With the current crop of 5W40's available you might consider trying M1 5W40 SUV or Redline 5W40. While the Redline might protect better at the drag strip I am betting that M1 5W40 SUV will hold up better in retararding corrison.
 

Al

Messages
19,256
Location
Elizabethtown, Pa
The Redline or the Royal Purple have (to me) shown no better results than the Mobil 1 . I think Amsoil gives slightly better results than the Mobil 1. The Castrol GC gives possibly slightly better results than the Mobil 1-possibly-not enough comparisons to really tell. But by and large 10W-30 Mobil 1 for summer and the 5w-30 M1 (winter or all year around for your climate) would more than fill your needs. Delvac 1 5W-40 would be tough to beat by any oil.
 
Messages
9,427
Location
Pensacola & Vero Beach FL
I owned a 98 Buick Regal GS (240hp version of the blown 3.8) for a couple years and it ran very happily on the M-1 10w-30 (early on, it had a couple fills of Syntec 10w-30 before I learned the Syntec truth). I would not consider any of the racing oils in this engine for a couple reasons. First, without the normal detergent package, you'd need to change it very often, and two, if you do have a problem and make a wty claim and GM finds out you've had a racing oil in there (note lack of API "legality" in most racing formulae), you will have an uphill battle on your hands. IMO, the few percent hp gains the racing oil might give you are far outweighed by the risks.
 
Messages
9,448
Location
USA
The 40Wt. will provide better ring sealing, less noise and vibration and will be less volitile. THe lower volitility means less deposits and less chance of rings sticking. I doubt that you will lose enough power to even be noticed on a dyno going from 10W30 to a 5W40. With the Redline you might actualy gain some HP as the Cf seems to be less with the Redline 5W40. The big improvments that Delvac1 bring to your ride is ring fill control, corresion protection whiles just sitting around, good cold flow numbers and great valvetrain protection under load!
 
Messages
926
Location
Ohio
Hey a fellow GP owner! [Smile] The parents ride around here is a 02 GP GT. It too has the 3.8L but it is not supercharged. It makes 205hp if I remember correctly. Since the car is still under warranty there are no mods to it what so ever, not even air filter. Until the car gets out of warranty it stays bone stock since we don't want to deal with the dealership hassle if so anything were to happen with the car. I've tried to talk dad into going over synthetic but the rule remains [Frown] All the other cars around here run M1 5w30. My truck has 0w30 soon to have a motorguard bypass. May I ask what mods do you have to your GP, as dad wants to modify his went warranty is up. Were looking for horsepower vs looks. Just to get some ideas that is if you don't mind me asking? PM me for my email address or post a reply, up to you. Our GP runs great with the stock 5w30 oil. I think it's Quaker State, I'm not sure on the brand,,,,AR
 
Messages
188
Location
Milwaukee, WI
I've been running M1 5w/10w-30 in my '97 GP for about 30,000 miles (103,000 on car) now with pretty good results. However, mine is a n/a car, so no superchager. I run the 10w-30 in the summer and 5w-30 in the winter. I notice that the 5w-30 tends to burn off more than the 10w-30, but the car burns so little oil that its almost irrelevant (1/4 qt in 6000 mile OCI with 10w-30 vs. about 3/4 qt with the 5w-30). I havent had an analysis done on the oil, but others have around here with M1 10w-30 and it holds up well in 6-7000 mile intervals. The engine isnt too hard on the oil, being an older pushrod design. I say either stick with the M1 10w-30 or, like JB said, kick it up to a 5w-40 which may yield some better protection given your mods and the fact that your car has a supercharged engine. I dont think you can go wrong either way.
 

Chris Fucik

Thread starter
Messages
12
Location
New Berlin, WI
Ranger, you've got to get your dad to understand that M1 absolutely cannot and will not give your dealer any cause to void your warranty. Any API cartified 10W-30 oil is ok. Remind him that M1 5W-30 is the factory fill for the Corvette and that most GM dealers carry M1 5&10W-30 and will upgrade your oild change to it if you ask. No warranty problems there. The Magnuson-Moss warranty act also prevents them from squawking about air filters, such as K&Ns. Warranty-wise, I'm already way beyond the point where I've voided my drivetrain warranty and I could not in good concience ask GM to fix anything if I blew something up. Strictly speaking, my warranty was void about a week after I got the car when the Thrasher cold air box and 3.4" {12% faster} supercharger pulley went on. [Big Grin] Considering that, with my last round of mods over the winter, I expect to be running the 1/4 mile somewhere right around 13.0 at 106 MPH, if I break something, it's my own damn fault. [crushedcar] [Roll Eyes] As for my mods {performance wise}: *Thrasher Cold Air Induction box with a 9" S&B Powerstack air filter *180 degree thermostat *Autolite 103 plugs, gapped at .056" *Digital Horse Power V1.0 PCM software *Thrasher interchangeable supercharger pulley system with 3.4" {12% faster}, 3.25" {17% faster}, and 3.0" {27% faster} pulleys *Intense Racing Gen1 1.9:1 rocker arms {stock is 1.6:1} *ZZP/Tech Edge EGR delete module {EGR module and tubing removed} *The Other Guys electroless nickel plated headers *Custom 3" pipe eliminating catalytic converter and U-bend for second O2 sensor *Caspers Electronics O2 sensor spoof module to replace second O2 sensor *Custom section between cat/U-bend replacement section and the factory Y-split before the mufflers with a 3" Dynomax bullet race muffler as a resonator, Flowmaster 3" to 2.5" reducer section and 2.5" tubing back to the Y-split. *GM W-body auxilliary transmission cooler kit *Firestone Firehawk SZ50-EP tires to help put power to the ground *Arriving by the end of the week or early next week: a set of 16X7" Motegi Racing FF6 wheels; 16lbs each versus 21lbs or so for the factory stock tri-spoke wheels. [Big Grin] I'b be happy to answer any questions you might have regarding how to make your GP quicker. I'm not sure if you're aware of the Club GP board or not, but it's a great resource for any questions you might have. The are something like 17,000 of us on there now. http://www.clubgp.com/ Also, since you are from Ohio, you are in close proximity to one of the top aftermarket vendors for the Grand Prix, Intense Racing. Put it this way, their turboed GTP now runs 10.3s in the 1/4 and expects to hit 9s this summer. Their Bonneville SSEI will hand Vipers their asses all day long. Check out the Ohio Club GP http://ohcgp.clubgp.com/ and the Central Ohio Club GP http://cocgp.clubgp.com/ {which is more closely associated with Intense} any you'll be hanging with the many of the fastest GPs out there. [Big Grin]
 

Chris Fucik

Thread starter
Messages
12
Location
New Berlin, WI
[Off Topic!] Might I ask; why can't a person edit their own posts? I can see not allowing you to edit others' posts, but why not your own? Over on the Club GP board, I frequently edit my posts to correct for typos and spelling errors; otherwise I'd look like a complete idiot, rather that just a part-time one. [Wink] For example, my post above is full of them. [Frown] Anyway, back to the subject at hand. So, nobody here thinks there's anything to be gained with something like RP Racing 21? The detergent thing might give me pause, but don't the race/street offerings from RP AMSoil and Redline actually have a detergent package? It's not that I have anyproblem switching back go good old M1, but, as my mod list would imply, my baby gets mothing but the finest and I'll go to great lengths for that last little bit of speed and power. [Big Grin] With all the uncertainty surrounding the "boutique" synthetics, I was contemplating switching back to M1 anyway. It's the only oil that comes close to a majority consensus when the question is posed over at Club GP. I just wanted to run it by the guys over here to see what you have to say. Keep the info coming! [Big Grin]
 
Messages
257
Location
palmer mass
hey everyone i just recently bought a 97 grand am 3.1 is there any modifications i can do to make this car more powerful it seems to be a little underpowered anyinfo appriacited
 
Messages
1,130
Location
California
You might want to search out some of the Made in Germany version of Castrol 0W-30. People have posted many excellent results with it here. However, for the conditions you have described I don't see any reason to work up a sweat about finding something other than Mobil-1 10W-30. John
 

Patman

Staff member
Messages
22,012
Location
Guelph, Ontario
quote:
Originally posted by Chris Fucik: [Off Topic!] Might I ask; why can't a person edit their own posts? I can see not allowing you to edit others' posts, but why not your own? Over on the Club GP board, I frequently edit my posts to correct for typos and spelling errors; otherwise I'd look like a complete idiot, rather that just a part-time one. [Wink] For example, my post above is full of them. [Frown]
You can definitely edit your own posts here, although there is a one hour time limit.
 
Messages
507
Location
Michigan
I have a 97.5 Regal GS w/ the supercharged 3.8 engine. Great engine by the way..along w/ a few mods too (exhaust, t-stat,CAI, etc). The car now has 104,000 miles on it and the engine continues to run great. I got the car w/ 60,000 miles and the previous owner had the oil done at the Dealership every 5-6k miles on it. It appears w/ Dino 10w30. I switched it to Synthetic right away and it's had either M1 or Castrol. For the summer 10w30, winter 5w30. I do feel the car likes a little heavier oil and this summer I'm going to run 5w40 instead of the 10w30 to see how it acts. I would agree w/ previous posters that any of the oils listed would be a good choice. I'm partial to M1 and will stick with that.
 
Messages
418
Location
OR
I have a '97 GTP w/3.4 blower pulley and open cone. It's had M1 10W-30 most of it's life. It's now at 121k mi and runs like new. I pulled a plug recently and it looks perfect and there are absolutely no leaks. I've been tempted to increase the viscosity a tad by going to a 5W-40 or spiking the M1 10W-30 with a quart of 15W-40 or 20W-50. However, I've resisted the urge to tamper with a known good formula for this engine. Don't underestimate good old M1 10W-30.
quote:
Originally posted by Chris Fucik: 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.
 
Messages
418
Location
OR
I have a '97 GTP w/3.4 blower pulley and open cone. It's had M1 10W-30 most of it's life. It's now at 121k mi and runs like new. I pulled a plug recently and it looks perfect and there are absolutely no leaks. I've been tempted to increase the viscosity a tad by going to a 5W-40 or spiking the M1 10W-30 with a quart of 15W-40 or 20W-50. However, I've resisted the urge to tamper with a known good formula for this engine. Don't underestimate good old M1 10W-30.
quote:
Originally posted by Chris Fucik: 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.
 

Patman

Staff member
Messages
22,012
Location
Guelph, Ontario
quote:
Originally posted by davefr: I have a '97 GTP w/3.4 blower pulley and open cone.
I had that exact car with only those two exact mods on it, and mine ran a best ET of 13.78 at 100 mph, on a 60 degree day. I only owned the car for one year, and only used Mobil 1, changed about every 5k. I ran 5w30 in the cold months and 10w30 the rest of the time. Never did a UOA though. I wish I had! I drove that car hard. (like I do with all my cars) [Smile]
 

pmt

Messages
148
Location
MN
quote:
Originally posted by JohnBrowning: The big improvments that Delvac1 bring to your ride is ring fill control, corresion protection whiles just sitting around, good cold flow numbers and great valvetrain protection under load!
To: JohnBrowning Could you tell me what is in Delvac 1 that protects against corrosion in a "stored" engine better than other oils? I'm interested because I have a car that sits all winter in my garage, and I worry about rust and corrosion taking place inside the engine during that 4 1/2 month period. I know that I could start it up every week or so, but without driving it it's hard to fully warm the engine. Why don't I drive it in the winter? - Minnesota salt! Thanks. pmt
 
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