icsmike

Just curious Im using 20-50 now Im thinking about 15-40.

Randy V

The same stuff I use for weekend driving.

Mobil 1 - 15-50 SuperSyn.

Sharkbody

20-50 Amsoil or 15-50 Mobil 1 performance.

BC

The 5/40 seemed like it was shooting too much up the oil filler, so I switched back to 15-50 amsoil. I would like a 15-40 sythetic if I can find it.

I bought some 10-30 mobile long life just to see what it would do in the car.

Gretch

15w50 Delvac......it goes in everything in the fleet, except the sleds. I get it by the gallon, and it is dirt cheap at $2.25 a quart.............NAPA, but you gotta ask them to get it.

Tom. M

20w50 Redline synthetic at the moment....only $4.50 a quart at our local Cut Rate Auto Parts...

and when I'm feeling rich...I run to the BMW dealer for the Castrol TWS...10w60...best oil ratings I have seen...good ratings from many people (including Doug downunder)..but it's like $9 per quart..

later,
Tom
89GT

BC

Do you have the links for the UOAs on the 10/60 or are they on the bobtheoilguy?

4.50 for redline? Jazus.

Is the Delvac synth? I don't recall.

blau928

15w-50 Redline. DE & Street.. No complaints, no burning oil, no issues with engine... 277,000 miles and counting... Used the Redline 20w 50 for more than 170,000 miles. First 100,000 miles were done using Mobil 1 20w 50 I believe... It was a long time ago, so I'd have to dig out records of the oil to be exactly sure of the M1 grade..

I pay about $9/Qt for redline by the case....

HTH,

anonymousagain

Just replaced with Shell Rotella-T 5w-40 synthetic - it was $13 something at Wal-Mart for the big bottle; also an oil that Doug reported having very good qualities. Mobil T&SUV was bucks at nearly $6/qt and only sold by the quart at several WM's I checked by me.

I recall Doug's report about using the lowest 1st number for better flow (typically 5w US, since 0w is rarer and $$$), with a 40 or 50 higher rate number. I show 2.5 to 3bar idle and 5bar under power, along with much much faster decrease from 5bar to 3bar at start-up than the 10w-40 I previously had. Actually, the 10w-40 idle was 3.5bar. I definitely feel better about warm-up damage prevention than I did before.

Nevertheless, consider your climate and driving use. I know Bill Ball found some higher engine heat with his SC car running 5w-40 at high speeds with high outside temps, so he runs 15w-50 M1 IIRC to be safe and have some peace of mind. Start-up concerns me the most and since NorCal doesn't scorch 100 temps much and I'm non-SC'd, I prefer the flow protection of the 5w than to gain the 40 to 50 rating for extreme usage.

You should definitely consider at least <20w first number for better flow.

Bill Ball

Just to clarify, my problem was that as I came to a stop after the uphill leg of an open road race in 95F heat, the idle pressure showed less than 1.5 bar and I think the pressure warning came on. I killed it quickly when I saw the pressure and let the car cool down. No problem after that, but I decided to go back to 15/50. Perhaps at 160K miles I have a bit of bearing wear dropping the pressures lower than other may find. For many 5 or 10/40 is probably great, and perhaps for me it is fine except in extreme desert heat.

85fortheDrive

I elected to go with a synthetic motor oil in the hopes that it might provide benefits for our 84 928S 5spd with 200K+ miles. I chose Quaker State 10/30 synthetic.

Not sure that I chose wisely because I now have minor oil leaking, which I believe is do to the thinner nature of the synthetic. Just an FYI.

mpesik

Jesus, time to change the oil!
20-50.
A bitch in the winter!

hinchcliffe

The lower the number in front of the w the more it will flow at low temps. The higher the number after thatthe better the viscosity is at high temps.

If you're driving in the winter, below 32 deg, go for something about 5w-10w, if its always over 50 deg. when you start the car anything 15w-20w will be fine. Being that our eniges run quite hot at normal temp the second number should always be at least a 30 but if you are in higher temp areas go up to a 50-60.

When I go to the track on anything over 70 degs outside I'll run 20w-50, for my normal driving 30-45 minute intervals under 5500 rpm I'll stick with the 15w-40. I don't run the car much when its under 40 degs.