View Full Version : Winter oil for a '95 ti with 140,000 mi (Northern IL)

11-04-2003, 06:33 PM
I've used Mobil 1 10W-30 without much loss (half a quart over the service interval) but decided to switch to Mobil-1 5W-30 for the winter months.

I changed the oil on 01 September, I'm halfway through the service lights, and I've used just a little over a quart so far. So I'm wondering if I REALLY need to keep 5W-30 in the car over the winter (Northern Illinois). The service manual thinks I'll be just fine except for a few bad days in January and February.


11-06-2003, 12:51 AM
I would think a 10-30 would make an excellent winter oil (particularly Mobil-1).

I run 15-50 Mobil-1 in the summer (well, year round as I don't drive the car in the snow at all) and if I did run through the winter, I would think 10-30 to be a good choice.

As long as the motor does not labor to start (assuming a good battery and starter) either will be OK. The problem is flowability as the engine warms. If the car is in a heated garage, any oil would be fine. BUT if the car is outside in -10 temps it will have a bit of trouble pumping that molasses up to the cams, causing wear.

Perhaps it's best to err on the thin side for the winter, and just check at every fill-up. An extra quart of Mobil-1 is cheaper than a top-end re-build I think...

11-06-2003, 06:05 PM
I run Mobil 15w-50 as well. It was 20 degrees this morning and started just fine. Of course my car was in the garage, so it was probably 10 degrees warmer. This is one example of where synthetic oil really shines, it is much better for temperature extremes. However, I do not think I would try to start my BMW if it was sub 0 degrees F with 15w-50 oil of any type, synthetic or normal.

10w30 is a good bet for any weather, unless you live in Alaska or north US where it is regularly below 0 degrees F. Just make sure you let your engine warm at idle for about 30 or more seconds before you rev it up. Use the time to put your seatbelt on, adjust the radio, scrape ice off your car, etc. You don't need to let your engine get warm before you go, but you need to give it time for the oil to flow and thin up a bit.