0w-20 in LS1 - I'm I crazy?

wwillson

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All, I am going to be driving from Chicago to San Francisco to LA to Phoenix and back to Chicago in my 5.3L Suburban in about 3 weeks. I'm very curious to get opinions if you think I'm nuts for considering Mobil 1 0w-20 for this long run? The thin oils have been giving some really great UOA's and Terry always says that the oil temp will run considerably cooler with thinner oils. The 0w-20 isn't very much thinner than the 5w-30 and I would probably save a bit on fuel consumed. Thoughts? Thanks, Wayne
 
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Please do not do this!!! I saw a UOA on another board of an LS1 that ran M1 5w-30. It was horrible. The 5w-30 is very thin. IMO the LS1 cannot take such a thin oil. You are going to get excessive wear. Try GC, Synergyn 3w-30 or some other oil.
 
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Dont do it! Results will not be catastrophic but you will have more wear than with a thicker oil in my opinion. Where did you see a UOA of a LS1 based engine ie 4800-6000 that liked thinner oil? If you can point me to such threads I will stand corrected. The oil for the LS1 based engine appears to be the German Castrol Syntec 0W-30. if you dont have any Autozones around where you live to pick this up try to find another thick 30 Weight ie around 12.0 cSt @ 100ºC or a thin 40 Weight like the Castrol Syntec 10W-40 or anything else around 13.0 cSt @ 100ºC. Gene [ July 11, 2004, 01:07 AM: Message edited by: Gene K ]
 

wwillson

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quote:
Originally posted by Gene K: Where did you see a UOA of a LS1 based engine ie 4800-6000 that liked thinner oil? If you can point me to such threads I will stand corrected.
Gene, I haven't seen any, I suspect it's because not many folks have tried this yet. Wayne
 

wwillson

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I'm pretty convinced not to use 0w-20! I have a good supply of Chevron Delo 10w-30. I like the increased additives of a HDEO. Do you think this oil would be a good choice? Wayne
 
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Did not mean to come on to strong. Its just the wear numbers have tended to trend down as viscosity went up on the LS1 based engines. I am not against it as a experiment but if you do it I would not want to try it in the 120 degree temps you are likely to experience in the Desert SW in early August. I would definately take a UOA of your current oil and then a UOA of the 0W-20 on return. I suspect the wear metals will be fairly high but as I said I doubt it will be catastophic as long as water temps and oil temps stay under control. This would tell you if it was a good idea long term. But again knowing the condition you may face it seems a extreme test. Then again i may be wrong and the wear numbers may be outstanding. The Delo 400 10W-30 is a very good choice with a approximate 11.1 cSt @ 100ºC. SAE30 is 9.3-12.49 so it is just in the heavier half of the range. Gene [ July 11, 2004, 01:39 AM: Message edited by: Gene K ]
 
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wwillson, can you afford a new engine if things go bad? If you can, go for it! Only promise you do a UOA before they tow your vehicle to the local garage. Not that I think your engine will self destruct or anything similar, but I'd hate to be the guy to recommend such a move and then have things go really bad. [Big Grin]
 

Patman

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The LS1 definitely does not like an oil this thin, stick with something thicker than 11 cst at 100c. That is what I would consider the absolute minimum for an LS1 that is going to see any hot oil temps at all. For very hard driven LS1s they see their best wear with an oil of 12 to 14 cst for the most part.
 
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The 5.3L is not a LS1, its a LM7. It is based on the same architecture. The LS1 is a 5.7L all aluminum engine. LM7 ENGINE GAS, 8 CYL, 5.3L, MFI, IRON, GM LS1 ENGINE GAS, 8 CYL, 5.7L, SFI, ALUM, GM LS1 and LM7 are GM option codes I have a LS1 in my 2002 Pontiac Trans Am WS6 and the same engine was used in base Corvettes up to the 2004 model year.
 
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Usually just refer to the 4800-6000 as the "LS1 Family" or "LS1 Based" I refuse to call it a Gen III Chevy Small-Block because its not. The engines have no more in common than the Ford 460 and 6.8L Triton V10. Gene
 
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quote:
Please do not do this!!! I saw a UOA on another board of an LS1 that ran M1 5w-30. It was horrible. The 5w-30 is very thin. IMO the LS1 cannot take such a thin oil. You are going to get excessive wear. Try GC, Synergyn 3w-30 or some other oil.
Wait a minute. So one UOA you saw SSDude and you base everything on that? Lets see, Corvettes rarely have engine failures due to oil. Plus, we've seen some great M1 5w-30 UOAs in LS1s track driven. Mobil 1 WAS 9.8 cSt for about 3 years and that was what was put into the Corvette. Now we have Mobil 1 SS 0w-20, with better additives and it's about 9.0 @ 100c. I agree with everyone that a thicker oil (around 11-13cSt) is ideal for the LS1, but I don't think this would hurt the engine at all. I say go for it.
 
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As I stated earlier I think a 0W/5W-20 would be less than ideal for mid-summer temps in the Desert SW in this engine but I do doubt it would be catastrophic. However when you step outside the known and safe territory you take certain risks. If I was going to do it I would consider a accurate oil temp gauge and consider maximum safe temperature 150ºC. Also if I was doing this simply to optimize mileage and make a point I would use Torco SR-1 5W-20 as with a viscosity of 7.31 @ 100ºC no one could claim its almost a 30 weight. I really would like to see the results of this test but must council caution. Proceed at your own risk. [Off Topic!] DG has also been a GM Consultant off and on. You dont have to look to far to figure out where the starting spring rates for Z06 development came from. Gene [ July 11, 2004, 02:46 PM: Message edited by: Gene K ]
 
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quote:
Buster, In the end you agree with me therefore, your point is moot. My comments are not based soley on one UOA. It was used only as an example. I also should have mentioned Redline in my initial comments. Dick Guldstrand, the Corvette racer told me that he is now seeing LS1/LS6s that use Redline with 200,000 and 300,000 miles on them without a drop off in performance. None of these cars used M1 He feels that M1 5-30 is too thin for the LS engines. He is an engineer and knows more about the LS1/LS6 than most.
Interesting. I don't think the 20wt would kill his engine though is what I'm saying. I know these engines like a thicker oil as mentioned. SSDude, I take it this guy is a RL fan? Don't these engines go that far on M1 as well? [I dont know] Regardless, thats an impressive endorsement for RL. [Cheers!] [ July 11, 2004, 03:40 PM: Message edited by: buster ]
 
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quote:
Originally posted by JustinH: Just for the record, what does GM recommend for this motor? Isn't it 5W30?
5W-30 is preferred, 10W-30 is OK above 40°F and synthetic 0W-30 is OK to use below 0°F of continued exposure. I have owned a 1999, 2001 and now a 2004 5.3L as well as a 2002 5.7L LS1. I use(d) 5W-30 in the 5.3L and use 10W-30 in the LS1 (rarely driven in cold weather) always synthetic btw (Amsoil).
 
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I'm my opinion, the best oil I've seen for the LS1 is Schaeffer's 15W-40. It has a superb additive package, it's a medium 40W, it's 25% PAO and it will keep your engine nice and clean for years to come. I plan on running this oil as soon as I'm done with my current OCI. A good second option would be GC 0W-30. I would not run a 20W oil in an LS1. If anyone wants to test a 20W oil, then I'm for it. I'm not that brave however!
 
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Came in kinda late, but again from my experience our lt1/ls1 engines like thicker oils, dont put a 20 wt oil in there, oh man i would never ever even slightly consider doing this, especially a m1 0-20, that thing must flow more than water [Wink]
 
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