My oil has truned to slush

Gordie,

I run Mobil 1 10W30 in my ol' Chevy 1/2 ton. The other day it was -10F (roughly -23*C) and it cranked over and started no problem. Back when I lived in Northern Ontario I used Castrol Syntec in my vehicles and never had a freezing problem either

I'd highly suggest a swap to synthetic, you will notice a difference when you start em' on those cold mornings!

Doc

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That jug must have gotten contaminated with some moisture at some time. I've had plenty of regular oil sitting in the trunk of my cars at those types of temperatures and they have never exhibited that type of condition. Sure, it will pour like molasses, (especially 15/40), but there has never been any sign of moisture in it. I'd be taking that jug back to where you got it.

Ian

I broke the seal on the jog and last time I checked oil floats on water so any water would be on the bottom anyway. My wife came home less than 10 minutes later and when I went to show her the oil was just fine in that short length of time in the house. Tonight I topped up her truck with Mobile 1 but my old Dodge oil burner isn't going to get the expensive stuff - no way.

-- Best Regards Gordie

Mobil One. I would also consider moving to a warmer climate. Damn thats cold!

Hmm, I had to have an emissions test so I put off doing an oil flush and change because it was cold. Well, I got up in the morning at 6am and it was -30C and I was stuck doing it then. The oil was sitting outside (not in the vehicle) and although the oil was thicker than normal, it sure was liquid and poured out fine. 5W30 weight. Coldest oil change I ever did. And I passed the test no problem 95 astro 4.3L with 320,000km. rick

Looks to me like you could use 0W30 Mobil 1. It does make cold weather starting a bit easier. Don't worry about that first number being low. Remember that when cold even that grade is thicker when cold that it is when hot. And, is thinner when at operating temperature (100C) and is supposed to have the same viscosity as any 30 weight oil.

I was away on vacation for a week, and when I got back last Friday, the daily high for a couple of days had been -1F. When I went to check and see if it would start, it was -14F and it cranked a bit slow, but started up fine. Mobile 1 5w30 in a 1988 4.3L S-10. Go to synthetics, it will help enormously.

Big Chris

"Doc" wrote:

Lots of miss-conceptions about the meaning of the numbers and the letters..

0, represents the weight or flow properties of the oil at low temperatures, my memory isn't what it used to be, but I believe 0 degrees F. The W means winter weight, the 30 means that it has the weight or flow properties of 30 weight oil at 100 degrees.

Also on oil will be other letters, like SA, SF, or CD, CF. The first letter designates fuel, S for gasoline, C for Diesel. Some oils meet both requirements. If the API seal doesn't list both S and C then it is only for the one it does list. The second letter has to do with manufactures requirements, the "higher" the second letter, the newer the requirements it meets.A-H are obsolete J is rated for 2001 and older, L for 2004 and older, and M is the current. In diesel it gets trickier. A-E are obsolete. Many have a number after the letter, such as CF-2, Diesel/1994 and older/severe duty TWO Stroke. As opposed to CF-4, Diesel/1994 or older/severe duty four stroke. The diesel designations also have to do with sulfur content in the fuel, and wither or not the engine uses exhaust gas recirculation such as CF-4 PLUS

this formproduced by API is very informative.Whitelightning

temperatures,

Correct. 5W30 is a winter weight. At 0C (32F) it has the same viscosity as straight 5 weight at 0C. At 100C it has the same viscosity as straight 30 weight at 100C.

Conventional oils get adjust their viscosity with the aid of viscosity improvers (VI). VI has poor lubrication qualities.

The beauty of synthetics is that they do not thin as much when they get hot and therefore can create the desired multi-viscosity without the use of VI.

I often hear it said that you should not use 5W30 during warm weather. I have found no good reason to make that statement.

On an older car, pre 90-94 I would probably agree with that statement as tolerances weren't as tight, and 80's or older I think it would be asking for failure. Then again a lot has to do with where you are at. Death Valley, south Texas, New Mexico, Florida warm weather is a lot different than Canada, Washington state, Virginia etc. And a good number of auto makers are stating 5W30 for year round. Part of me wonders though how much of that recommendation has to do with fuel mileage, as opposed to longevity. As to the value of Syn over conventional, I don't know. I've never run it, not in personal vehicles which are kept till no one else wants them, usually

250-300k miles, nor in any of the big rigs I drove.

Whitelightning

I got into synthetic back when the only weight offered by Mobil 1 was 5W20. I put it in a 450 Cu in Chevy engine that had about 75000 miles on it. It used a lot of oil when pulling heavy loads. I was convinced the oil was vaporizing due to heat. I put in the Syn. and oil usage disappeared.

Now when I think a bit more about it 0W30 might be even better in hot weather than 5W30 or 10W30. I say that because when heated from 0C to 100C the 0W30 does not thin as much as the other two. Based on that I would expect that the 0W30 would thin less as it gets even hotter and perhaps the

10W30 would thin the most as it gets hot.

As for fuel mileage, I would think the only place 5W30 would help is when the engine is warming up. Once at operating temperature all the 30 weight oils are supposed to be the same viscosity.

I think all vehicles (gas engines) that come with turbos specify the use of synthetics.

Back in 1977 I had Quaker 10-30 in cold weather and the car had no oil pressure when it started and did a little damage quickly. Much later I believe they were taken to court and made adjustments to people who lost engines due to the same phenomenon you mention happening withing their oil pans. I have not used any Quaker State product since.