My 06 Ram diesel has the block heater. If I plug in the heater at night, the coolant temp will be about 100 degrees in the morning. I have verified this with a scan tool, just to satisfy my curiosity. I’m sure the coolant in the radiator will still be ambient temp.
I went on a weeklong snowmobile trip in Wright Minnesota (about 30 miles west of Duluth). The WARMEST it got that week was 15 below zero. The glow plugs did stay on much longer than they normally would here in Indiana, but the truck started normally. If a diesel will start after sitting a week in well below zero temp, there is no reason a properly tuned, properly maintained gas truck won’t start.
I don’t play around with batteries. I load test the battery (or batteries) in my vehicles every fall, and replace them at the slightest decline. I also don’t cut corners on the CCA rating, get at least what came factory.
I got 9 years out of the original batteries on my Ram, I just replaced them again last fall after one failed a load test. I’d rather replace them in my driveway at my convenience, as opposed to the parking lot at work in the rain or snow.
When did batteries get so expensive?! I spent 320 on a pair of 950 CCA Duracell, and those weren’t the most expensive batteries they offered. The puny battery in my neon was 80 bucks.