Winterizing the White Whale - Page 2 - Fuel Economy, Hypermiling, EcoModding News and Forum

Diesel_Dave · 10-25-2011, 12:14 PM

Today the weather was a little colder (high 30's), but warm up was about the same as yesterday. FE wasn't as good (only 35.2), but that was due to catching some lights badly as well as a school bus--all towards the end of my commute. Prior to the disruptions my mileage was tracking about what it normally would be on a warm day, maybe even a little better.

Before starting out, I crawled under the truck and put my hand on the oil pan to see how hot it was getting. With the heaters on for 5 hrs it was definitely warm, but still cool enough that I could comfortably keep my hand on it. I was concerned about potentially coking the oil, but I know I'm fine now. I'm not sure how hot it was, but operating temp is >200 F, and I know I wouldnt be able to keep my hand on that. I think I may try leaving them on all night tonight and seeing what happens.

Diesel_Dave · 10-27-2011, 06:08 PM

I'm pretty confident that the heaters are helping my cold starts now. Today, the temps were in the high 40's and it was raining. I got 40.1 mpg on the way to work this morning. That's the best I've ever gotten in the rain. Granted there was a 6 mph tail wind and traffic was good, but it's still great.

euromodder · 10-28-2011, 11:15 AM

40 mpg from a truck isn't just good - it's excellent !

Diesel_Dave · 10-28-2011, 11:33 AM

Quote:

Originally Posted by euromodder

40 mpg from a truck isn't just good - it's excellent !

Thanks, but again I must point out that's from the in-cab which reads ~15% high. So 40 mpg is probably more like 34 mpg in real life (which is still great).

Today was the coldest day of the year so far (in the 30's). Got 39.1 mpg today. Pretty sweet for the coldest day of the year.

Diesel_Dave · 11-11-2011, 09:05 AM

Today was the first freezing day. It was 28 deg F when I left home. Still managed 37 mpg.

Last night when I left work it was 34 deg F. It took 5 mi for my coolant temp gauge to even start reading (140 deg F). This morning, with plugging in, it only took 2 mi.

Diesel_Dave · 11-22-2011, 11:10 AM

So I found out that my oil pressure gauge is actually just a dummy gauge. grr! There's not actually a oil pressure sensor, there's only an oil pressure switch that triggers the gauge if the oil pressure is excessively low--otherwise the gauge just reads a estimated oil pressure (which I'm guessing is based on engine speed and coolant temperature). C'mon Chrysler! Really?!

So my assumption that my oil pressure gauge was an indication of how my oil pan heaters were working was incorrect.

So I'm working on actually measuring the coolant and oil times (vs. time plugged in). I'll post more when I get more data.

slowmover · 11-22-2011, 06:27 PM

Yeah, pretty irritating when I came across it in one of AH64ID's posts on CF. I like your explanation of how it might work, hadn't thought of that. Genuine engine oil temp & oil press gauges now seem like a good idea.

Diesel_Dave · 11-23-2011, 09:24 AM

Quote:

Originally Posted by slowmover

I like your explanation of how it might work, hadn't thought of that..

I'm only guessing it's based on speed and coolant temp. Speed because I can see it goes up when I'm at higher rpms, and also because that would phisically make sense--the oil pump is tied to the crank so more rpms mean more oil flow. I'm guessing it's alos based on coolant temp because I definitely can see that the oil pressure "gauge" reads lower when I pre-warm.