Temperature Effects

[Diesel_Dave]

Originally Posted by mcrews

Dave,
how long is the comute?
Does the vehicle start outside (so the temp has settled in overnite)
or is it in the garage?

My commute is 24 miles each way. The truck is outside, but I use my coolant and oil pan heaters at home (in the morning). In the evenings it's a true cold start. That's one thing that's not captured very much in the average temperature metric--cold evenings or worse for me that cold mornings, because the heaters help in the morning. That said, it's usually is warmer in the evening, because I'm usually leaving right before sunrise in the morning--which is the coldest point of the whole day.

Also, I should add that I try to avoid using the heater/defroster until I get to full operating temps (usually takes ~12 miles). The exception to that is when I need the defroster/defogger to see clearly. If it's just a little fog, I've learned that cracking the window about an inch with take care of it, but if that doesn't work I use the defogger/defroster.

I have a garage, but the truck is literally about 4 inches shorter than the garage. Plus, my wife's car goes in the garage (of course), and putting it beside hers would make it really tight side-to-side as well. I figured it's just not worth the effort (and risk of damaging the garage, my truck, or her car). Plus, as it is, I can back up the driveway and park at the garage door so I can coast out in the morning. Plus, I'd waste fuel carefully jockeying it into place in the garage.

[PaleMelanesian]

5 years of commuting data.
Averaged all mpg results at each temperature point.
10 mile commute.
Parked outside, so fully cold-soaked.
Heat off until warmed up (takes most of the trip, so pretty much always off)
No AC in summer.


That slight flattening at 80+F is because of AM/PM temperature differences. Max morning temp is low 80's so anything above that is driving home, 100 ft elevation gain over 10 miles.

[mcrews]

Dave & Pale,
GREAt CHARTS!

How much do you blame on the winter gas formula???

[johnunit]

This whole thread is great.


Makes me hope for good things from my Prius that I've never driven in warmer than 45ish degree weather

[Ladogaboy]

What about Kelvin?

Man, this is sad, though... no wonder my mileage has decreased (only ~ 20* drop... F, I guess I must now add).

[slowmover]

Originally Posted by mcrews

Dave & Pale,
GREAt CHARTS!

How much do you blame on the winter gas formula???

Winter Diesel Fuel

I've seen from 4% to 12% as an estimate (when temps are factored).

[slowmover]

Originally Posted by PaleMelanesian

5 years of commuting data.
Averaged all mpg results at each temperature point.
10 mile commute.
Parked outside, so fully cold-soaked.
Heat off until warmed up (takes most of the trip, so pretty much always off)
No AC in summer.


That slight flattening at 80+F is because of AM/PM temperature differences. Max morning temp is low 80's so anything above that is driving home, 100 ft elevation gain over 10 miles.

Definitely one of my favorite infographics on this site. (Forgot, what part of the state you are in?)

.

[Diesel_Dave]

Originally Posted by mcrews

How much do you blame on the winter gas formula???

Pure #1 diesel has about 4% less energy content than pure #2 diesel. Keep in mind, that most areas don't go to a full #1 blend either. Granted, other properties (like cetane rating, etc.) change as well, but especially on common rail diesels like mine, energy content is the main property that matters. Personally, I think a lot of people blame the fuel when it's actually the temperature.

[PaleMelanesian]

Originally Posted by slowmover

Definitely one of my favorite infographics on this site. (Forgot, what part of the state you are in?)

.

Northeast corner. Pretty far from you. "Everything's bigger in texas", including the distances.

Oh, and we don't have a different blend of winter gas, so it's all because of temperature.

[slowmover]

Originally Posted by PaleMelanesian

Northeast corner. Pretty far from you. "Everything's bigger in texas", including the distances.

Oh, and we don't have a different blend of winter gas, so it's all because of temperature.

Yeah, Corpus Christi to Texarkana via Dallas is almost 600-miles. But you're close to Pittsburg and some nasty [great] hot links. Are you old enough to remember Big Al (at Lone Star Steel)?

And you're outside of an EPA Attainment area, so no "summer gas" either. Prior to reading this site I'd have thought that, say, past 90F that mpg would taper off, maybe even decline.