One of my indie shops tells me that 0w30 (synthetic) is best, and is recommended by BMW. Another shop tells me that 0w40 is too thin for summer and that I should be using 15w40. Who is correct?
Sounds like you're talking full synthetic oils in all cases. Without some valid comparison tests or insight from an expert on it all, I'd say.... depends in part on your driving, driving style, annual mileage driven, oil-change frequency, and probably other factors as well. I use Amsoil 20w-50 for summer/track driving, and 0w to 10w - 30 or 40 for winter driving. If you don't drive the car much, push it hard, track it, or accumulate enough mileage for seasonal oil changes, then something to work all year around and cover all bases might be appropriate. Your winter weather can be a factor as well - if you regularly see sub-zero temps, a 0 weight for winter driving might be appropriate. If the lowest you see is, oh.. say.. teens, then a 10w-something might be just fine. If you push the engine at track events, then I'd think you'd likely want at least a top range of 40, if not 50. If you live in Alaska and drive it all year around with summer track driving, I think I'd say changing seasonally would be better than trying to run a 0w-50 oil (not that anyone even makes one, that is..)
I know oil is a touchy subject. Everyone has their own opinion, so here is mine. If the oil question is for your E30 in your picture, then I would stay far away from 0w and 5w oils if you are in the lower 48. In your car manual or if you have a bentley manual (which you should!) if gives the appropriate oil weights based on outside air temp for your car. I would probably stay in the 10w to 20w range. I live in Southern PA and run 15w-50 year round. It rarely gets below 20 degrees at night in the winter here. I use Red Line. Beautiful E30 by the way! GR
Yeah, I had been using 10w30 year-round since I don't track or autoX and I don't drive the car when it's <40 degrees (my heater core is busted). I don't know why this indie guy said BMW recommends 0w30. My Bentley manual indicates that 15w40 would cover 95% of the ambient temperature range here in eastern Massachusetts, so the second indie shop is right on. I have only used 0.5-1 pint of the 0w30 (mixed with 10w30) so I think I'll be OK there. Thanks for the compliment on my E30. I've got six pints of Mobil 1 0w30 if anyone lives near me and you want some discounted oil!
btw, swapping out heater cores is not all that big of a job (besides dealing w/ spilled coolant) - if you do it yourself, just make sure you note the orientation of everything before you pull it apart, including which engine-side coolant hoses are upper & lower. The center shift console piece is basically plastic-covered hardened styrofoam, so it's not all that flexible, try not to stress it much as it is removed. Don't remember what the Bentley manual says without looking, but I'd say try to get the coolant out of the core before you remove it (blow it out w/ compressed air, or suction perhaps?) - just to attempt to keep from dumping coolant on the carpet. Maybe a couple of rubber stoppers jammed in the inlets. I think there's some valve too, make sure that's not your problem (Bentley manual might cover testing that as well...)
I think the 0w oils are for new BMWs when BMW NA started needed to make EPA MPG standards. So once again it was a change due to polictical reasons rather based on good engineering principals. Stick to what you have been doing with the 10w/30 and you should be okay. It is usually best to commit to an oil and stay with it, rather than keep changing weights and brands. I agree that you can probably fix the heater core yourself, just be sure you have the Bentley Manual and take care. The heater core is buried pretty deep, so set aside a couple days if you have never done this before. If you find yourself getting frustrated, step back and take a break, because that is when you will break something you don't want to. Good Luck, Grant
I was told that no synthetic oils should be used in our cars because of their age and that using them would create an oil leak. I use Castrol GTX 10w-30 or 5W-30 depending on season...I live in NY so the winters are pretty harsh.
Again oil is very subjective. I use Red Line Synthetic oil in all my cars, including my 84 318i and 88 M3. I use it in the trans, diff, power steering, and motor. I don't have to add any oil in my 318i between oil changes. I think the best thing is to use an oil you trust and then stick with it. Don't keep changing brands. Synthetic does not "cause" oil leaks. What happens is that synthetic is able to get into smaller spaces than conventional oil, which is good by the way. But on an old car, it can get past oil seals that have aged, where conventional oil will not. So if you switch to synthetic you might start seeing higher oil consumption compared to what you had with conventional oil. Again my opinion here, but I would not use anything less than 10w in the lower 48, the older BMW engines required heavier oil. But don't take my word for it, refer to your owner's manual or Bentley manual. They give a very nice graph that shows what oil to use depending on outside air temp and what kind of driving you do. I think most independent BMW mechanics would agree. GR
On the heavier oil note...what about something like 20w50? I'm in Mississippi, so hot summers are kinda the main, but winter is pretty unpredictable. Daily driver '91 325, 70 miles a day minimum.
I've got 20W-50 in my bird right now. Summers are pretty hot here as well in southern Connecticut and haven't had any issues with using this oil in my car, even at the track. For the winter, I'm going back to 10W-40.
The manual says 15-50 for the Pacific Northwest. The latest E30 I just picked up (1990 325ia) came with full records since new. The owners all ran 10-30 based on the receipts. Of course the engine is plugging along fine at 170k miles. It's now getting 15-50 because I know better, but would probably be fine if it got 10-30 for the rest of it's life. I used to run Mobil 1 synthetic in another of my E30s (1987 325is), but was burning oil. My local shop has been suggesting the Vavloline high mileage stuff to their high mileage BMW customers. So swithed to that and oil consumption went down a bit. Plus the oil is not as expensive. Put it this way, most E30 BMWs have other problems long before the engine blows based on lubrication issues.
I use Castrol 10W-30, since i bought my car about a year ago. Havn't had any problems. I only burn about less then half a quart every oil change. And I change the oil every 3,000 miles.
