Oil Preference

[drifter_for_life06]

What motor oil do you guys prefer to run in the warmer months(i.e. like now(April) through September)?

Gonna try to change over to some Redlin 5w30 if i can find some, but AAP doesnt carry Redline products anymore

[Nismo_Freak]

You need to run a 15w50 in the summer.

[xero1]

i use mobil 1 syn. 10w-30 in the summer and 5w-30 in the winter, i wouldn't recommend using 15w-50 on an sr20det with low mileage, you will loose hp and cause more wear on the engine. 15w-50 is good for an old american engine, but its not recommend for modern engine with tight bearing clearances.

[xero1]

this is from the s14 sr20det service manual(ma-11) "5w-30 or 10w-30 is preferable regrardless of driving conditions."

[drifter_for_life06]

nismofreak, can you give any explanation behind the 15w50.....

[DrifterProdigy85]

10w30 Mobil One Full Synthetic. 15w50 sopposably is too thick for the SR oil pickup and can starve the engine of oil. I remember Scott (Enthalpy) talking about it once before.

[Nismo_Freak]

If you live in 100 deg. ambients in the summer are plenty for running that. The only thing I have noticed with a 15w50 is on cold start up you have to limit the RPM or you will run a ton of oil pressure. Limiting the RPM also helps to lower ring wear until the oil comes up to temp.

And forget what the FSM says, it's for a stock engine being driven by Mrs. Daisy. The turbocharger, bearings, and a number of other components run at considerable differences in frictional temps when you run higher boost.

Therein lies the reason why you should run the heavier oil, it's due to the increased thermal loading in the engine. If you are running an oil cooler, then you can get away with a lower weight oil because you have control over oil temps.

[xero1]

15w-50 means when the oil is cold the, the weight of the oil is 15; and when the oil is up to opperating temp. the oil is 50 weight. the reason why nissan recommend a 5w-30 or 10w-30 is beacause of the tight clearance in the engine, for example the rod bearing clearance is .0008-.0018 in. i don't know how abuse you're sr20det is, but my engine only have 39k miles on it, and its clean on the inside. if you're engine has been abused it might need the thicker oil to keep it from knocking and burning oil.

[Nismo_Freak]

Tight clearance? The standard oil for a turbo aircooled H6 engine is a 15w50 in the summer. Thats an engine that is a tolerance nightmare, and very very finicky about it's tolerances, and relies on the oil to cool the engine.

Also the 0.0008 - 0.0018 range is a standard rod bearing tolerance. Even the old Austin Healey motors back in the 60's used a 0.0010 tolerance on the rod, and most V8's are built around the 0.0015 - 0.0022 range, at least here locally.

[drifter_for_life06]

i dont beat my car, i hardly ever rev past 3-4k for the fact gas is so damn expensive

temps are hardly ever 100* here

[Nowhere]

If you live in 100 deg. ambients in the summer are plenty for running that. The only thing I have noticed with a 15w50 is on cold start up you have to limit the RPM or you will run a ton of oil pressure. Limiting the RPM also helps to lower ring wear until the oil comes up to temp.

And forget what the FSM says, it's for a stock engine being driven by Mrs. Daisy. The turbocharger, bearings, and a number of other components run at considerable differences in frictional temps when you run higher boost.

Therein lies the reason why you should run the heavier oil, it's due to the increased thermal loading in the engine. If you are running an oil cooler, then you can get away with a lower weight oil because you have control over oil temps.

You've got some reading to do.........

http://63.240.161.99/motoroil/index.html

[drifter_for_life06]

i love bitog.com

[Nismo_Freak]

You've got some reading to do.........

http://63.240.161.99/motoroil/index.html

Eh, I've read that before. He runs on and on about low weight oils.

The best situation as described by Ferrari is to use the 0W-40 around town and the 10W-60 “racing oil” on the track. It has to be that “hot” track though.

I think I'd trust Ferrari whom has been developing engines since the dawn of the sports car over a physician that has a knack for oil.

Blackstone has this to say:

Engine owners often stray from manufacturers' recommendations regarding viscosity of oils. The engine builders dyno-test their engines using a specific viscosity oil, so when you use the viscosity they recommend, you are working with a known result. Going to another viscosity is an experiment, but it's usually a harmless one. For the sake of efficiency you want to run the lightest grade oil in your engine possible, within limits. We are seeing that trend for newer engines, for which the recommended grade is getting progressively lighter. The common 10W/30 has become a 5W/30, and some manufacturers even recommend 5W/20 oil. On the other hand, we can't see (in oil analysis) where it hurts anything to run heavier 10W/30s or even 10W/40s in modern automotive engines. The heavier oils provide more bearing film, and that's important at the lower end. If your oil is too light, the bearing metals can increase. If the oil is too heavy, the upper end metals can increase. The trick is to find the right viscosity for your particular engine, which is why we suggest following the manufacturer's recommendation.

[McRussellPants]

Anyone who runs less than 15W-50 either doesn't have an oil pressure gauge or drives like my grandma.

Let it warm up for 30seconds to a minute before moving the car and then 5 or so before revving over 3500 and your golden.

Amsoil > *

[180fan]

15w-50 Motul 300v here. If you're running a turbo, you'll want the 15w-50.

[180fan]

Anyone who runs less than 15W-50 either doesn't have an oil pressure gauge or drives like my grandma.

Let it warm up for 30seconds to a minute before moving the car and then 5 or so before revving over 3500 and your golden.

Amsoil > *

Good point with the warmup especially if you've rebuilt with forged pistons and experience piston slap.

[2_Liter_Turbo]

I run 20w-50 Royal Purple. Of course my car will endure 120 degree summers, so I'm fine. I couldn't find 15w-50 in redline or royal purple when I went to the "local oil store".

[JesusLikesKFC]

hmm i wonder about ny thoguh. iv been good with 10w30 but always ran 10w40 in the high compression ka. temps here vary from 50 one day to 80 the next pretty often. ill probly try out 10w 40 and see how that goes.

[drifter_for_life06]

will i be fine with 15w50 int he winters here in PA?

[vutony]

will i be fine with 15w50 int he winters here in PA?

thats too thick for the winter, preferably 10w30

[themadscientist]

15W50 Mobil 1. Been using it for years. My CA18, L20, RB20 all run it. My bike did too with no clutch slip either. My lil two-stroke uses Motul full synthetic.

[wildacexxx]

10w30 all summer long. will probably run it in winter also

[pearlS13]

I run mobile1 5W50 in the summer and i love it. My oil temp never gets above 85*c and I have good oil pressure. The weather here doesnt get really really hot for me to have to go with a thicker oil.

[Fenvy]

bump for myself to read later

[sl87]

ive heard that synthetic oil is bad for the turbo...true?? ive used 10w30 of royal purple, redline, and mobile 1. i liked purple and mobile a lot. ive been running 10w30 during summer. Thnking about changing to 5w30. really 15w30?? interesting

[aleph1]

IMHO, i would never run 15w-50. WAY too thick. it just doesnt make sense to me, not only would it be harder for that to make its way into tight spots, but it wouldnt sheer very well hence not letting the engine rev as quickly.

Living in CO, we get some pretty hot summers out here as well as cold winders, all 4 seasons.

I run 5w-30 for winter and 10w-40 for summer in RP(or really any synthetic is good). My previous SR that came in the car i bought had been maticulously maintained with 15w-50 and, surprise, had slight rod knock when i bought it (from SoCal). The oil was most likely the issue via Occams Razor.