Best oil for GM 3.8L?

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Has anyone actually tried Delvac 1 in an L67?? I've always been curious if a 5W-40 might be a good switch after a 100k mi "break in". M1 10W-30 tends to be a tad thin and just curious if one notch thicker might be good for a high mileage L67? Has anyone tried a Delo 400 in a L67?
 
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quote:
Originally posted by davefr: Has anyone tried a Delo 400 in a L67?
I forgot which engine has the supercharger or is n/a? I've got an n/a version that I'm currently running Delvac 1300 in. Will get an analysis when I drain it in a few thousand more miles.
 
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quote:
Originally posted by davefr: Has anyone actually tried Delvac 1 in an L67?? I've always been curious if a 5W-40 might be a good switch after a 100k mi "break in". M1 10W-30 tends to be a tad thin and just curious if one notch thicker might be good for a high mileage L67? Has anyone tried a Delo 400 in a L67?
I'm running it(M1 SUV 5W40) in mine which is a 99 GTP with 53,000 miles. So far so good. REAL smooth and quite. Also I haven't noticed any difference with gas mileage too. I do have some mods so that's why I decided to try the 5W40.
 

Chris Fucik

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Just to focus this discussion a bit more and steer it in a slightly different direction... Assuming that Mobil 1, AMSoil, Redline, and Royal Purple will all hold up to the 6,000 mile OCI I plan on sticking to, which of those oils, in thier 10W-30 street grades, is likely to reduce friction the most, i.e. which will produce the most power? I realize the differences will be minimal at best. [ May 11, 2004, 01:04 AM: Message edited by: Chris Fucik ]
 
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This past weekend I did an oil change on my 3.8L SC Regal. I mixed in 4 quarts of the 15w40 Delvac with one quart of Mobil's 5w30 synthetic. All seems well and maybe it's me, but the engine seeems a little quieter too. I think this will be a good summer blend for the car.
 
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That's an interesting blend. I was thinking a good summer oil would be 3-4 qts M1 10W-30 with 1-2 qts Delvac 1 5W-40. I'm really tempted to try Delvac 1 in my GTP but my next oil change will be late summer/early fall. I'm wondering if 5W-40W is too heavy for a L67 going into the cooler months. Does anyone know if Delvac 1 is considered a heavy or light 40W? If it's right on the cusp of being a 30W I might give it a try.
quote:
Originally posted by edvanp: This past weekend I did an oil change on my 3.8L SC Regal. I mixed in 4 quarts of the 15w40 Delvac with one quart of Mobil's 5w30 synthetic. All seems well and maybe it's me, but the engine seeems a little quieter too. I think this will be a good summer blend for the car.
 

Patman

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quote:
Originally posted by davefr: Does anyone know if Delvac 1 is considered a heavy or light 40W? If it's right on the cusp of being a 30W I might give it a try.
Delvac 1 is around 15 cst at 100c, so it's more on the middle to thick end of the 40wt range.
 
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Well, personally I am partial to the 10W-30 maxlife on 3,000 mile oil changes on this engine. My 2002 Camaro and late 2000 Firebird 3.8 V6s both ticked noisily on mobil1, but are silent as ever on the Maxlife. I have one UOA right now for the 10W-30, and I will be doing another one in 1,000 miles (give me a month and check back). http://www.angelfire.com/my/fastcar/ for info about my Camaro [Smile] I intend to try the 10W-40 version and UOA it as well, just to see if a higher weight helps or hurts. I run a 160F thermostat and several other mods, nothing insane yet because I'm a college student, but I still remain as a prime member on firebirdv6.com. Welcome to the oil board [Smile]
 
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Chris, Since you know me, you know that I tend to take the road less traveled when it comes to mods and maintenance on our cars. I've been totally happy and very impressed with my latest choice in oils...Schaeffer's Supreme 7000 10W30. I use a Baldwin filter in the stock length (have my own personal reasons for that) and it too has performed flawlessly. I know you don't want a blend, but do try to remain open-minded when it comes to oils. I was a firm believer in a full synthetic myself too until I started talking more about oils with my buddy who runs a speed/machine shop up by me. He's been building engines and racing for the last 30+ years (has a Monza that runs 7s with no power adder!), and never in his career has an oil impressed him as much as Schaeffer's has. One of his customers that always bought Kendall oil from him for his H-D tried Schaeffer's on his recommendation, and came back to the shop a couple hours later after he changed it, and believe it or not, his oil temperature had dropped 40°! This was found to be consistent too, not just a one time fluke thing. I have noticed in my car since switching from M1 10W30, a noticeable reduction in internal noise (not like the 3800 has a lot to begin with) especially upon cold startup, and also when the engine is really hot after flogging it a while. If you read into the VOA and UOA sections here, you'll find some very impressive numbers for Schaeffer's. A lot of times they're better than those of popular full synthetics. These results were the final push for me to give it a try...I still had to get the notion that a full synthetic was better for my engine than a blend out of my head and dive into something that would have normally given me the willies had I not known better after getting educated here. If you ever wanted to give some a try, I can get it for you and meet up with you somewhere to deliver it to you. PM or email me at ClubGP (since I'm there more) and I'll let you know about costs. I don't want to step on anyone's toes here. [Off Topic!] Got a new PB too! 14.926 @ 92.63 with no DHP or rockers!
 
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