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.

edit: duplicate info

My '4.5 CTD idles up above 900 if it is cold enough automatically on factory settings. My cruise hi-idle is not turned on.

While I don't have any first hand experience from what I have read the new V-8 trucks coupled with the 6 speed transmissions perform at a level at least close to the older diesels, specially the pre HO models.

Old-Biscuit wrote:

If you have the factory high idle enabled (cruise control ON....set---idle comes up) then you can increase the idle via the 'accel' button......just push and idle will increase each time you push it.

Yes, true. I can set it anywhere between 1000 and 1500 RPM using accel/decel.

ib516 wrote:

transamz9 wrote:

Do you have an aftermarket idle up feature? Makes a WORLD of difference on my 5.9. My factory idle up is at 900 rpm. My Bully Dog idle up is at 1150.

Yes, I have a Predator programmer that allows me to enable the cruise control idle up feature. In these very cold temps we are experiencing right now, I set it for 1150 RPM + or -, and that allowed the engine temp to stay at 145*f when the truck was stationary. Usually it drops right off the low end of the temp gauge.

If you have the factory high idle enabled (cruise control ON....set---idle comes up) then you can increase the idle via the 'accel' button......just push and idle will increase each time you push it.

cyberiankhatru wrote:
As th OP, I appreciate all the info and opinions here. I'm leaning toward the HEMI but before I decide I'm going to talk to some mechanics I know and see if they have anything to add. I know the diesel would be better but the additional initial cost will cut into my new TT fund...meaning more time with the existing camper. Plus I need to test drive both of them.
Thanks again and Merry Christmas!

Give us your impressions when you do!

If I walked onto a Ram lot, it truly would be a toss-up as to whether I drove out in a 2500/6.4L, 3500/6.7L DRW CTD, or 1500/3.0L TD. The 1500 would do what I currently need a truck to do and get great MPG...the 3500 DRW would open the door to a TC down the road...and the 2500 Hemi would be a 420hp happy medium between the two.

Hoping my focus will narrow before later in 2014 when I actually do walk onto the lot...

fly-boy wrote:
Maybe its just me but I will never go back to a gas motored HD pickup- never! I would buy a car for daily driving and rent a diesel pickup for trips before buying an HD truck with a gas motor. I get everyone has different needs... and this is just my personal preference.

But- After 15 years of HD diesel pickups- the smile is still there. :)

Not trying to change your mind- I "get" the diesel love, I really do- but have you driven a late-model gasser with a solid transmission behind it, i.e. 05-newer V10 with 5 or 6-speed Torqshift, GM 6.0/6-speed combo, or a GM or Ford 6.2L in front of a 6-speed?

Perhaps you have and still feel that way and I totally respect that, I'm just curious if, when you think of gassers, you're thinking of the offerings from 10-15 years ago as opposed to now.

As th OP, I appreciate all the info and opinions here. I'm leaning toward the HEMI but before I decide I'm going to talk to some mechanics I know and see if they have anything to add. I know the diesel would be better but the additional initial cost will cut into my new TT fund...meaning more time with the existing camper. Plus I need to test drive both of them.
Thanks again and Merry Christmas!

ib516 wrote:

transamz9 wrote:

Do you have an aftermarket idle up feature? Makes a WORLD of difference on my 5.9. My factory idle up is at 900 rpm. My Bully Dog idle up is at 1150.

Yes, I have a Predator programmer that allows me to enable the cruise control idle up feature. In these very cold temps we are experiencing right now, I set it for 1150 RPM + or -, and that allowed the engine temp to stay at 145*f when the truck was stationary. Usually it drops right off the low end of the temp gauge.

Yes, the temps you are having are COLD!:E

Try leaving you heater plugged in overnight. Plug it up when you get home and leave it. It won't hurt it. Works well for me on my F350.