15w40 Working well in the saturn for the summer, but winter?

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Nov 13, 2002
I've gotten good results back on running this 15w40 Delvac 1300S in my 1994 Saturn SL1. But I'm thinking this is not gonna be the best oil for our prety harsh ohio winters. What I'm thinking about doing is picking up some mobil1 from target for $3.69 a quart. However, they don't have the 0w40 I've run in the past. Does anyone think running 3 quarts of 5/10w30 M1 and a quart of the 15w50 M1 would get decent results? Am I correct in thinking that would put the viscosity of the oil somewhere in the area of what I'm running now but with significantly improved cold weather properties? Or should I just forget about saving the money and put in the 0w40 I've used in the past? --Matt
Mixed viscosity oils are not the arithmetical average. I don't know if there's a chart for multi-vis oils, or if a test has to be performed to find out just what you have. Why not use Castrol German 0W-30, or Delvac 1 5W-40, or any other good oil with good low temperature performance? How many changes will you do in the winter?...two? Ken
it'll probably be about 15k miles of driving over the winter. Any decent PAO synthetic oil should be able to make 7500 mile intervals. The delvac was OK'd by blackstone to go for 5k miles. I don't really wanna have to order oil and I don't really want to go with a 30wt oil since the 40wt does so well in this engine. Any other comments on mixing the 15w50 and 5/10w40? I know a lot of LS1 owners do it with good results. As far as delvac 1 go's there's no store that sells it within 100 miles of where I live. That would probably be the optimal choice but if I can get away with the mix at this cheap per quart price I'd prefer to do that. --Matt
0w-40 mobil 1 is what id vote for. just me though. however, if you want easily accesibility and an easy starting oil (should be anyways), id go for M1 15w-50 esp. in the summer time. that my vote at least. no wait, ny vote is for a 50/50 mix of M1 0w-40 and 15w-50.
mkosem, I vote for the 0W-40 but an alternative would be to use three quarts of 5W-30 and one quart of 15W-50 mobil 1. I think this would be closer to a 10W-40. There is only a little difference in the 5W-30 and 10W-30 in the HT/HS viscosity. There is more of a difference in the viscosity at lower temps between these two oil.
Even with just one quart of the 15w50 mixed in there, you'll severely degrade the cold weather properties of the oil. I wouldn't put a single quart of 15w50 in there for an Ohio winter. Just pick a 5w30 or 0w30 that has a viscosity close to a 40wt (such as Amsoil or German Syntec)
Without doing my homework, I would just recommend sticking with 15W-40. BUT select the synthetic 15W-40 with best cold crank sim. numbers (I honestly don't know who has the best (lowest) - shop the specs!) EDIT NOTE => And if these oil cold temp numbers don't seem low enough for your area then you can move towards a 10W, 5W, 0W....40 [ July 26, 2003, 09:00 AM: Message edited by: Pablo ]
I lived in Ohio for approximately a quarter of a century and don't remember any sustained periods of winter weather that would even approach the cold cranking capabilities of almost any conventional 15W-40... I can see where this is a possible problem in the Arctic, but O-H-I-O? Hey, it's all up to you what floats the ol' boat! mkosem: How is that Saturn specialty aftermarket company that's based in Dayton doin', anyway?
SPS is the company you're thinking of and they seem to be doing prety well. Schaeffers seems to have prety good cold cranking numbers in the synth. Maybee I'll go with it. --Matt
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