Does Synthetic Make Your Tractor Start Easier?

[Ledgemere Farm]

Just a general question. I have never used sysnthetic, but was wondering if it would ease start up during cold temps?

 

[Dargo]

According to the chemical engineers, yes. There are several good web sites for information, but one that is written for those of us without a degree in chemistry, http://www.bobistheoilguy.com/ gives analytical, non-biased, information in plain English. In cold weather, the "pour point" (The lowest temperature at which oil will pour or flow when it is chilled without disturbance under definite conditions (ASTM Method D 97). It gives an indication of the lowest operating temperature for which particular oil is suitable) is better with synthetics.

 

[JJT]

I noticed better cold starts when I switched from a conventional 15w40 to a synthetic 5w40. The 5w is much thinner at 0 degrees.

I used to run 15w40 in my generator, 2 weeks ago we had a power outage and at -10 the gen would start and immediately shut down, (low oil sensor was killing the engine even though the crankcase was full). I switched it over to 0w30, (used religiously in my cars), and the genset ran fine. I'll be leaving the 0w30 in the generator.

 

[gsxr1100]

so you where using a dino oil (15w-40) at zero temps????? If yes, wow.

 

[RalphVa]

As I recall, the xxWxx ratings are based on oil viscosities at 100 F and 210 F, think 40 C and 100 C now. Synthetic oils will generally have a bigger range of xxWxx numbers than non-synthetic. You can get a synthetic, for instance, that's 0W40. This is a bigger range than any dino oil ever could muster.

At starting temperatures of 20 F down to perhaps as low at -20 F (and further north, even -40 F/C), oil viscosities can really thicken up, particularly if that xxWxx range is smaller.

Someone here mentioned pour point. Oil generally won't pour once it reaches about 1 million centistokes viscosity. Some oils reach this and won't pour. Others solidify due to the presence of wax molecules. Synthetic oils will generally have a lower viscosity at lower temperatures and don't have ANY wax molecules. These properties will help a lot in providing less resistance to flow at starting engine temperatures.

Ralph

 

[Ledgemere Farm]

Well, I put in Mobil One 0W-30 today. It is in the twenties here now, so of course it fired right up. We will see what happens when the temp drops again.
Thanks for all of the input!

 

[gsxr1100]

the 0-30, even dino, should be fine down to zero.

 

[BobCorazza]

As above... Synthetics generally out perform petroleum oils at either extreme. With synthetic oil that requires little (or no) viscosity improvers there is really no reason to not use a wide spread oil like a 0w30, 5w30, 5w40, 10w40, 15w50.

From various sources & manufacture's here is the MINIMUM temps for various "W"inter specs :
0w : <-20
5w : -20
10w : -5
15w : 5
20w : 15

Note that these are the lower temp limits. What I personally go by is :
0w : <-20
5w : -20
10w : 10
15w : 15
20w : 30

Occasionally Maryland sees single digit temps, so my tractor and autos all run 5w30. The motorcycle takes 20w50 in the summer and 10w40 in the winter, but I don't ride in temps much colder than mid 20's.

 

[RalphVa]

0wxx will work down to -40. It is the ONLY one that will get to your valve gear before it starts smoking from lack of oil at -40 F/C. This is based on tests done by Exxon (actually Imperial) Research a few years back with transparent valve covers on a car being started at -40.

Ralph

 

[JJT]

I keep the generator in the garage, it rarely goes below freezing and it's heated when I'm out there. I've used 15W40 in all my air cooled engines for 25 years with no issues. In this gen for 7 yrs and this was the first problem. I'll be sticking with the 0w30.