Will a 10 mile commute kill a diesel?

ib516 wrote:
As many of you know, I'm a huge fan of the Cummins diesel. The two I've owned (2002 and current 2007 5.9L) have been very reliable, easy on fuel (not like a Prius, but good for a HD truck), and powerful pullers.

That said, I will be taking a serious look at a 6.4L Hemi powered 3500 SRW when I am shopping for my next truck. I have a 12 mile commute (one way), and I have the whole grill blocked off with a winter front. My truck is garaged (not insulated or heated garage, but it is slightly warmer than outside, and it is out of the wind). I run the block heater on a timer that comes on 4 hrs before I leave for work.

This morning, the outside temp was -13*f, and the engine temp on my truck finally got to about 1/3 on the gauge (160*f coolant temp on the ScangaugeII) when I pulled into the parking lot at work - just started to blow warm air out of the heater. That gets old....fast.

The 5.7L Hemi is ok for light work in the 2500s with 4.10 gears - as good as any other smallish gasser, but the 6.4L Hemi has that little bit more for me to seriously consider it. I know a 6.4L Hemi in a HD truck won't be great on gas, but they do say the 6.4L Hemi will get better mpg than the same truck with a 5.7L Hemi due to the MDS system on the 6.4.

Well, I can give you my real world experience with my truck. I have a similar commute (roughly 24 to 26 miles round trip). The new 6.7 seems to warm up tons faster than the old 5.9. When I remote start it, after 3 minutes it idles up to 900 or 1000 rpm. Even with a cold start, the truck always reaches 190 degree coolant and 190 degree plus on the oil by the end of my commute. My duty cycle is roughly 40% highway when I'm doing strictly work commute. I get warm air blowing right after 1.5 miles of driving, head temps tend to hit 150 degrees by mile 2. I've noticed that with the colder weather, I've never exceeded 199 degrees on oil temperature. The coldest its been around my parts is 8 degrees. I don't run a winter front, all open all the time since we tend to have milder weather in the winters here west of the Cascades. The only item that never really seems to fully warm up on that short commute is the transmission, it has a hard time gaining any heat over 130 degrees in the cold. On a highway trip longer than 20 miles one way, it gets to its typical run temperature range which seems to be about 160 degrees.

Hopefully that gives you some food for thought.

edit: weird, my signature didn't show up. Well anyways I own a 2013 Ram 3500 crew cab, Cummins, srw, 3.42 rear end, 68rfe transmission. I'm getting at worst 18mpg. Best mpg I've gotten ever is 22 on a trip that was 90% highway. All mileages are unloaded.