fuel mileage - Diesel Forum

alharke · 12-21-2002, 06:01 PM

finally got my 99 E-350 psd out on the freeway for about a 2 hour run at 70 mph pulling a small 6x8 covered trailer with a couch and loveseat in it and 3 adults and 3 young children in the van and im a little disappointed with the 10 mpg i got especially since i live in mid michigan where its reletively flat. shouldnt i get better mileage especially with 3;55's and such a light load?????? any ideas? [img]/ubbthreads/images/graemlins/shrug.gif[/img]

Yardbrew · 12-21-2002, 06:22 PM

Yeah, unless you were pulling straight into the wind and the trailer sticks up above your van, you should get a lot better than 10.

In fact, you should get within 2-3 miles of what you get without pulling anything with a trailer that small.

First question: Did you absolutely top off the tank to where you could see the fuel before and after the 2 hr run?

Second question: What MPG do you get running 70 mph on flat ground?

I usually don't try to measure my MPG unless I go a thousand miles and top off the tank before and after. Just too many variables on a short run.

Yardbrew.

PJC99 · 12-22-2002, 12:45 PM

Yardbrew is right. There are many variables and it's tough to get an accurate indication based on one trip. Around town I get like 11-13 MPG. Cruising on the highway (70-80) I get 18-20 MPG. Loaded heavy I get around 15-16.

Those are summer MPG's....I get like 1-2 MPG less in the winter.

molnb · 01-09-2003, 03:16 PM

I have a 2001 E-350 Club Wagon PSD with a 355 rear. My first diesel, never again a gasser. I have about 48,000 miles on it now. I drive over 30000 miles per year, 8000-10000 towing a 8500lb TT. towing I get between 10-12 MPG, depending on wind and hills usually 65-75 MPH on interstates. Commuting in the suburbs of northern NJ I get about 14-15 ( little less now in winter)and on non-towing highway trips I get between 18-20MPG at fairly constant Interstate speeds. Towing in the Rockies has not been a problem with the 355 rear. It will slow down to 42-45 MPH on I-70 going up to the Eisenhauer Tunnel, but mostly it just motors along at highway speeds keeping up with the traffic flow.

Yardbrew · 01-10-2003, 10:10 PM

Bill,

Do you have an exhaust gas pyrometer on your van?

I'll bet the temps get alarmingly high when you are pulling that much up steep hills.

The power is there to pull the trailer but the intercooler to cool the turbo is not present.

Yardbrew

E350PSD · 01-12-2003, 09:24 AM

Yardbrew,

I just moved from CA to AR towing a 20’ utility trailer. The trailer:

Trailer
Rear View
Inside View

was custom built and has a 12,000# GVWR. I am using it to move my household stuff and machine equipment. Although the trailer weighs 3,500# empty you can load up to 9,700# (1,200# over the GVWR) when using the equalizing hitch.

My first load was at the limit and I thought maybe I’m pushing it too much. After pulling 1,600 miles I am happy to report these motors love to work. Yes, the 3.55 rear-end was a slight handicap but I managed 70/75 MPH in OD on level grade, 55/65 in 3rd on grades, and 45/55 MPH in 2nd on the real steep grades.

I was concerned about the EGT (pre turbo) but my experience was it’s not an issue. The stock motor programming limits itself to safe conditions even when pushed hard. What I noticed was the transmission temperature can quickly rise when the TC does not lockup - such as pulling steep grades. On 2 occasions I was ready to back-off because the trans temp was hitting 220F – I wasn’t EGT limited!

Typical grades had me around 1000F (green/yellow) and 190/200F on the transmission:

Gauges At Work

EGT 1000F, Tranny 200F, 57 MPH, GCWR close to 20,000# - can’t complain …

Oh yeah, my mileage is 13/15 city, 17/19 highway and 12/13 towing.

molnb · 01-13-2003, 10:50 AM

Thanks Yardbrew,
My next project is to do what many on this site have done and that is to install guages on the A pillar.
Other than knowing the exhaust gases are high, what can i do to keep them lower in those kinds of situations.

Yardbrew · 01-13-2003, 10:10 PM

Rob,

That is a NICE trailer. Makes mine look like ice age.

How are you solving the mirror problem?

My post turbo temps will hit 900 on a moderate grade if I hold it at 65-70. I figure that correlates to about 1100 pre turbo and I try hard not to get above that for any length of time.

Don't know what everyone else uses as a rule of thumb??? Am I being a fraidy cat?

If it spikes above that, my usual solution is to slow down or shift into a lower gear.

Yardbrew