What oil have you guys been running in your engines in the winter? I was told by the dealer to run 15W-40 in the summer, but was never told about any options in the winter. I hope I can run something thinner because of all the cold starts I go through.

 

I'm running 15w-40 and it starts fine down to 0F without plugging in.

 

I switch to a semi synthetic 0W40 for the winter months made by Esso. Good for starts down to -40 for sure.

Some guys I know run the Chevron 5W40 all year round and say its the way to go.

I would switch oils if you are near 0°F much. The pour point of 15W40 doesn't reach far below 10°F and you will get oil pressure much sooner, with easier cranking.

J-eh

 

Dog,

The XD-3 is NOW fully synthetic.....

Ive made the switch to Chevron Delo syn 5W40 and prolly gonna stay that way year round (or the 0W40 XD-3).....

 

It would be good to know where you are located, 90% of the US can get by with 15w-40 year round. I used to change to 10w-30 in the Montana winter but instead now run 15w-40 year round and plug in an oil pan heater when the temp drops below zero.

 

I'm in Alaska...temps vary from 30 to -25 in the winter. I have 10W-30 in it now. I just wasn't sure if that would mess up something in the engine once it gets warm 'cause it's thinner oil (oil pumps, injectors, piston rings, etc.)

 

For Alaska, Id recommend 0W40 or 5W40 synthetic....

 

The Dr gives good advice.

My understanding is running too light of an oil, 30w, when the temp is higher can be just as bad running too thick of an oil when the temp is low. That is part of my reasoning for running 15w-40 year round, it's not unusual to get 50° days in the winter here. I've seen it go from 62° to minus 25° in 12 hours!

One thing I've been told but never been able to verify is that if an oil has a weight spread of over 30 the high end will eventually degrade so the spread is 30.
For example a 0w-40 has a spread of 40, after time it would degrade to a 0w-30.

 

Well of course - "trust me Im a Doctor"....

 

for the most part it stays below freezing for the whole winter till around the end of March. Most of the cars run 5W-30 in the winter and then 10W-40 in the summer.

 

Hey Welder, I'm not sure what truck you've got, but I would make sure you've got the properly rated compression ignition oil in it and are not running spark ignition automobile oil in it.

FWIW, if you're running syn oil, you don't have to worry too much about viscosity spreads.

 

Thanks for the info Doc...

As for your oil grades, You want to keep the "40 part of the oil viscosity for Diesel applications. Its the 15, or 0 you want to have for the low temperature stuff. Remember, the 15W, 10W or 0W tell you the cold charactoristics of the oil, the 30, 40 are the base stock and upper temperature charactoristics of the oil. Even in the cold, the internal oil temperature can get pretty high under load and you don't want to use the 30 weight oil IMHO, its too light.

I would rather run 5W40 than 10W30. 10W-30 oil might not have the diesel application stamp or the Cummins approved detergents. GASOLINE OIL is not good in a Diesel engine.

Oil is the life blood of the engine, don't scrimp and save on that. Would you like the $5 blood transfution or the $1000 one at the hospital??



J-eh

 

I run Mobil Delvac 1300 15W40 in my TDI. Since I'm saddled with cooled EGR and closed crankcase ventilation, I wanted an oil that at least met CI-4/Mack EO-N Premium plus. Plus my climate is perfect for a 15W oil.

 

yeah, I knew about the different oil for gas engines and diesel engines. It sure would suck to watch your oil drain out like tar 'cause then you'd know you were in trouble! And I didn't know how 10W-30 oil would hold up in a diesel once it gets warm. I'll be switching to the 5W-40 in the winter and go back to 15W-40 in the summer.

 

This is true when discussing regular dino oils. The additives that are put into the oil (viscosity index improvers) will break down over time and if they break down enough it can cause the oil to change grades. 5w30 and 10w40 gasser oils experience this phenomena quite frequently. Also these oils with the wide spead and plentiful VII's will shear down easier meaning that in higher RPM's they are not protecting as well as an oil with a closer spread.

When discussing synthetic oils this is not so much the case. Synthetics rely far less on VII's to achieve the spread of their oils. They are more shear stable and maintain their grade much better than a dino oil.

For these reason you will probably never see a 0w40 dino oil, at least I have not seen one yet. If such a thing ever exist I would never consider putting it in any engine.