decision time

[JHZR2]

Hi,

The car is a 1991 BMW 318i, with the M42 4-cyl engine.
I currently use pennzoillong life 15w-40 in the car. I like the oil, but have just two issues with it: I wouldnt trust it in the winter time, and I get tapping noises at full temp, meaning that maybe my oil is too thin to keep adequater pressure in the hydraulic tappets.

That said, I am thinking it may be smart to change to M1 15w-50. The car was speced for 15w-40 or 50 or 20w-50, so I think the 15w-50 synth will be a nice fit. Plus, I would be OK with leaving it in the engine through the winter, because it is a synthetic and has better flow properties.

The problem is the car is used for short trips, so I would feel better using something cheaper. I was thinking of maybe trying delvac 1300, since they claim it also passes the spec to be a 10w oil in the cold. Maybe I just need an oil that has a bit thicker viscosity at temperature?

I do have a 2.5gal -4qts jug of longlife, purchased from wal-mart. Not sure what I ought to do with it, should I switch to the mobil1... Maybe use it in lawnmower service.

Maybe this is a no-brainer (because im cheap and dont want to not use the pennzoil, once I switch, itll be semi-permanent) but I do want to rid myself of the tapping, and my oil change is due...

I just need some help making the decision of what to do next...
Thanks

JMH

[ July 09, 2003, 11:56 AM: Message edited by: JHZR2 ]

 

[bretfraz]

Before shelling out the big bucks for M1, I'd try a 20W-50 first. Its summer time so no issues with cold cranking or pumpability. I know some folks with the same basic motor (1.8L) and the BMW shop they take their cars to always uses 20W-50 in that engine. These techs swear by it, especially in high mileage 1.8's. Keep in mind this is in my neck of the woods (Georgia) where is plenty hot and plentier humid so your local conditions might warrant a different choice.

But 20W-50 might be an excellent overall choice for you in terms of protection and price. Plus there are lots of products to choose from in dino, blend, or full synth.

 

[Eiron]

Hi JHZR2,

I can think of two options right off the top:
1) get some Penzoil 5W-50 full syn & do a mix for the remainder of the Penz LL you've got,
2) just hold onto the 15W-40 for use in other stuff like borrowed/rented vehicles that have been run dry, or (as you mentioned) in your lawn mower.

Pros for #1:
1) better cold and hot protection,
2) possibly better protection (& less noise?) at less than the full cost of going full syn.
Cons for #1:
1) takes longer to switch to what you want to use,
2) possibly not as much protection as using the full syn of your choice.

Pros for #2:
1) you get to immediately start using the oil you want,
2) you have decent oil on-hand that you don't mind sharing with others.
Cons for #2:
1) you have to keep the stuff around until it's gone,
2) you've already paid for it (I hate it when that happens!)

I'm not sure I understand why you "would feel better using something cheaper" simply because the car is used for short trips? I've put a little over 3k miles on my '90 Saab 900 in the past 9mos (about 98% short trip service), & I expect to have this same M1 15W-50 in my car for at least 10k miles. And it started fine down to about 12*F last winter (it got colder, but the car was in an attached garage at those times).

Maybe just buy 2qts of Penz full syn 5W-50 & try the mix, then if you don't like it you can save the remaining 15W-40 for all the lawnmowers in the neighborhood? (Boy, wouldn't you be a popular guy?!

)

(Sorry, I'm not sure I'm really helping here...

)