Should I use thinner oil?

[Flivver250]

A well tuned gasoline engine with a good battery doesn't usually need a block heater until you start getting in the extreme cold. Minus thirty and lower. Diesels can be more fussy. In Vermont -40 was common, -59 was the coldest I saw it on the mercury. Car parked outdoors, almost always started because I was prepped for it. At the extreme temps I'd start it up and go back inside for 15 minutes while my rig warmed up and defrosted. If I was back in Vt, I'd use 5-30 winter and 10-30 for the rest. If you have an automatic, I was always told to let it warm up in neutral, not park. Another bit of advice we always gave, don't use your emergency/parking brake in the frigid cold. They sometimes froze in the engaged position. BTW, another trick in lieu of a block heater was just have a regular lamp with a 100 watt bulb under the engine. They would keep the bay considerable warmer. My old landlord gutted his house with fire using coals from the wood stove under his jalopy.

 

[ranger101]

Something that I found to help my Jeep in the cold weather, I put the transfer case in neutral and put the transmission in 1st or 2nd gear and let it warm up. That way when I go to take off, my transmission and fluid are also up to temp

 

[Goatman]

Never had heaters on cars, but tractors, especially the one you need first thing in the AM.
There are two main ways they work. Block heaters are made to effect coolant. Pan heaters effect oil.
Running a block heater won't do much to warm the oil because it's sitting down in the oil pan.
For gas tractors we found the best way was a heat lamp on the carburetor to help the fuel atomize better in the cold. And blocking the wind from the bottom of the engine helps a lot too. It seems like the windchill is worse on our tractors than actual temp. Supposedly only animals feel windchill, but leave a tractor outside and it will start up a lot easier at 0* and calm than at 20* with a good wind chill.
Had to block up the clutch for 5 minutes. Even the trans in neutral would stall out a cold engine. Then 5 minutes in neutral so the trans oil can start to warm a bit. Then 5-10 minutes moving in a low (1st or 2nd) gear to warm up the rear end. After all that you were finally ready to get to work.
On the diesel tractors it was similar, but a pan heater would work better than a block heater. Fuel gel was the next problem.

 

[RaymondT]

5W30 Nov to end Apr plus block heater on a timer for 2 hrs before I leave for work. Runs better and the interior warms up faster. I also mix Redline MT90 and MTL which helps. Both choices are recommended on Redlines website for my AX5 transmission. About the coldest we ever see is -15C/5F.

 

[Aviatortroy]

I’m 10-30 all year round but I did notice if the Jeep sat a few weeks I would get some lifter noise for a minute or so. Added about 4 oz of marvel mystery oil and it completely solved that problem.

I unfortunately truly think your problem has not got do with the engine oil. Your symptoms sound very similar to what I went through and ended up being a bad fuel pump. Would occasionally not start. Other times it would start but not run very well until the pump built up good pressure, and it would take a few minutes. Fuel pumps don’t always just die completely.