Nope.........no other questions. I think we all know where you're coming from.

great now back to the real question.... I think 5w40 is the best choice all year round no matter what brand u chose, but i have never seen it offered in anything other than a synthetic, I may be wrong on this. So depending on wether or not u want to use synthetic would be a deciding factor. I know some people shy away from synthetics for their own personal reasons.

I have used Rotella 5W-40 synthetic and Mobil 1 Truck and SUV.

The car leaked/burned more Rotella than it does Mobil 1 despite the fact that it's clearly a lighter oil.(I have a few minor leaks on the injector pump)

I also am averaging about 2-3 mpg BETTER with the Mobil 1.

I highly recommend Mobil 1 Truck and SUV, year-round....

Sheesh...he simply challenged your statements...nothing personal, bro.

Delvac 1 or Delo Synthetic if you can find it.

I usually only buy Rotella, but . . . I only was able to find this:
http://i153.photobucket.com/albums/s.../Delvacoil.jpg

Edit to add:
Most place that sell Mobil product should be able to order I'm told . . . or on-line like here, http://store.avlube.com/fonfacsizcol.html 4 gal case:
http://i153.photobucket.com/albums/s...nz/Delvac1.jpg

Thats Delvac Super, a very good additive based mineral oil but thats for summers, its not Delvac 1.

I have found M1 5W40 (same oil) for $22/gallon at some walmarts (not most).

I thought M1 Truck and SUV was the same oil, not regular M1.

I believe that is correct . . . I assume that it is marketed to the trucking industry as Delvac 1 . . .

I also edited to add the Delvac 1 to my post above . . .

That's the oil I'm talking about (it's the only 5W40 they sell except for the "ESP Formula M" for new diesels, but it's now called "turbo Diesel truck"). The 5W30 is now called "Truck and SUV," just to make it more confusing.

https://www.mobiloil.com/USA-English/MotorOil/Oils/Mobil_1_Turbo_Diesel_Truck_5W-40.aspx

The reason is only synthetics can be made with such a wide viscosity range, no mineral oil can be rated at 0W.

One caveat from what I read at various oil forums. Many in Australia recommend against Delvac 1 in severe heat conditions. They have found negative effects rather than positive when compared to conventional mineral based oils, however they have also stipulated that they achieved excellent results using Delvac-I in extremely cold conditions. For heat, good old Delvac Super/MX or Delo 400 does swell. I myself have done extensive runs in 50C Rajasthan desert summer with very good results. Oil consumption was nil after hard 400 mile trek in the dust.

OK. I'm raising the BS flag. 15W-40 has been around for ages and has successfully been used in many engines with out any issues. I agree that 5W-40 (a synthetic) is an improvement over 15W-40 due to the fact it is a synthetic or quazi-synthetic and it also has a lower pouring point (5W vs 15W). The fact remains if it gets that cold you must use a block heater that will keep the block and hence oil warm enough that it won't be an issue. If it's that cold glow plugs alone won't work. You guys split hairs over which brand to use. Then criticize them if they don't use your brand and these oil wars start use this, no use this... USE A PROPERLY RATED OIL FOR YOUR ENGINE. DIESEL ENGINES REQUIRE "C_" Rated OIL NOT "S_" Rated.
Thank you for allowing me to RANT.

15W has a pour point of Appox -30 deg C
5W has a pour point of Approx -45 deg C
Pour point: The pour point is the lowest temperature at which an oil will flow. This property is crucial for oils that must flow at low temperatures. A commonly used rule of thumb when selecting oils is to ensure that the pour point is at least 10°C (20°F) lower than the lowest anticipated ambient temperature.

http://www.engineersedge.com/lubrication/pour_point.htm

In short... 15W is good to about -20 Deg C or -4 deg F

Wow.........how come I'm not stuck at the Marriott with ambient temps of 0°F?

I don't think they're going to let me run an extension cord through the lobby.

Because Brian Carlton you maintain your vehicle in tip-top condition. You're not the typical get in and drive type of owner. HMMM... Why in Fairbanks AK are plugs are provide at the Marriott? Oh YEAH they really do provide them... STIR THAT POT!!!!

Brian... UPDATED info in prior post.