Author Topic: Which oil? (Read 5316 times)

Sean_318is · « **on:** July 18, 2009, 07:44:42 AM »

Hi, I'm new to the M42 engine and I'd like to know which oil to use in my car?
Its an E36 iS with 175k miles. I've just changed the filter (nice and easy!)

I can get good quality oil from work in all 3 main grades, mineral, semi-(10/40) and fully synthetic (5/30)

Thanks, Sean

DesktopDave · « **Reply #1 on:** July 18, 2009, 03:34:38 PM »

I'd go for the full synth 5w30 during the winter months. It's a little too thin for really hot weather, like in Spain. Having said that, I've run synth 5w30 with good results year 'round in the Northern USA. It gives me slightly better fuel mileage. It's much "thinner" though, so look out for a few more oil leaks.

Sean_318is · « **Reply #2 on:** July 19, 2009, 09:58:33 AM »

Ok thanks

I live in south-west Britain and its never really cold or really hot. (It's July and it's been raining for a week or so

) I can always flush it and change it back again if it leaks!

DesktopDave · « **Reply #3 on:** July 19, 2009, 09:43:29 PM »

You'll get a different opinion about engine oil from everyone you ask. I'm not sure that synthetic is much better for old engines...but I am sure that it's best for gearboxes, transfer cases & diffs.

Make sure you change out the diff & gearbox oil with the highest quality synthetics too. I put $9/L 70w140 gear oil in mine...made an immediate difference...helps with shifting too. That will get you a bit better mileage & keep them running well. It's so much easier shifting during the occasional -20 degC cold starts here.

JP 91iS · « **Reply #4 on:** July 19, 2009, 10:05:23 PM »

I just put in some Mobil 1 15w-50. I'd heard that our engines like the thicker stuff. Also just ran some Lubro Moly Engine Flush. No leaks and it seems happy.

thebutcher37 · « **Reply #5 on:** March 24, 2010, 11:19:19 PM »

Hey im sorry to thread jack/ bring up an old thread...

But i would like to know if there is any problem using

Sta-Lube
Hypoid * Limited-Slip
SAE 80w90
Gear Oil
API/GL-5* PLUS

For my differential on my e30 318is w/4.10 LSD

I was going to originally use redline synthetic 75w90

but my father picked up the sta-lube for me, because thats what on demand-5 recommended to the mechanic at the auto-part store.
Im sure its fine, but I thought to ask because i have this problem where i have to be 100% sure.