Heavy Slow

neeemo · 06-10-2009, 08:56 PM

Starting this evening I'm going to run a fuel mileage test on my 8920lb '02 EB Q w/Voyager roof. I'm running Amsoil 15/40 ($145!! w/filter) and I'm going to drive no more than 55mph for all 37 gallons. Hopefully it'll be about 600 miles of pure and utter hell going 55.

Tom

Skywagon · 06-11-2009, 06:57 AM

I believe driving religiously at 55 MPH is good for almost 3 MPG more than the same route at 65. When I got my SMB, I went 55, telling myself that I wasn't in any hurry.

I always got around 17.5 - 17.9 MPG. I just got done with a 1200 Mi. drive to Canada at 60 -65 MPH and all three fillups were almost identical at 14.5 - 14.9. So, it seems as if THEY were right,;
mileage goes down quickly as speed increases. But, you're right, 55 is really SLOW!
Bill

geoffff · 06-11-2009, 10:49 AM

It's true -- it makes a huge difference. On the rare occasions when I'm driving 55 all day (windy scenic 2-lane roads) I get about 13 MPG instead of my usual 10 MPG.

But I live in Seattle, WA and play in Nevada, Utah, or Baja California Mexico. I just can't justify taking that 33% extra time driving slow (55 MPH vs 75 MPH) during the boring part driving down there. I want to get to Nevada in 1 day, and Baja in 2 days. Maybe I need to be like Jimmy Buffet and have multiple Sportsmobiles already there in my various destination locations.

-- Geoff

neeemo · 06-11-2009, 11:41 AM

"Maybe I need to be like Jimmy Buffet and have multiple Sportsmobiles already there in my various destination locations"

With fuel shooting up in price again, it may be cheaper that way.

Tom

avking · 06-11-2009, 12:11 PM

I agree with the go fast guys. I get about 8 or 9 MPG on my 6.0, but I am driving straight through from So Cal to Boise (right around 1,000 miles). I don't car if it costs me $100 or $200 more for fuel if I can cut drive time by almost 5 hours (75 instead of 55).

Ed in Montana · 06-12-2009, 06:15 AM

As Skywagon knows from the Moab 4WD training, I drive slow in almost all conditions. On Interstate driving, I rarely go over 65mph, cause I don't like how the van handles at 75mph plus. Too much bouncing around. Perhaps with Deaver springs it would feel more stable. Also, in heavy traffic, the stopping distance approaches one light year at higher speeds. Defiinitely looking at a brake upgrade next year.

Still, the SMB is averaging 15.5-16mpg on the highway fully loaded. Several times driving 55mph it's gotten almost 18mpg. I was surprised that the van averaged 13.5mpg during the three day 4WD training in Moab, over some fairly rough country.

j.whitbread · 06-12-2009, 11:13 AM

I drove to BC from SoCal with my V10 using the 5-Star tuner. The 87 econo program got me 13.3 mpg with a feather light foot. The performance is not so good. It doesn't run all that smooth.

I almost always use the middle of three program profiles. 87 performance, and it works really well. I haven't tested it for mileage, but it runs so much better than the econo profile, it's worth it. The V10s get around the same mileage towing or cruising it seems.

My van weighs less than 7000 pounds.

Skywagon · 06-12-2009, 11:18 AM

Ed-
Keep in mind that when you're figuring your mileage for the Moab offroading trip, that you spent a lot of time in low range putting a lot more miles on your odometer than you put on your truck!
Bill

deminimis · 06-12-2009, 11:20 AM

When bringing my then new to me 7.3 back from Texas, I got 16.8. However, speedo was off a bit (perhaps 1-2 mph over actual speed). Had a failing U joint so I was traveling around 55-60mph. 60 is a nice speed as it makes the math easier.

This past tank I pushed pretty hard usually going 70+ on the interstate (against strong headwinds sometimes), then slower on secondary roads with curves and various grades. Roughly came in under 14mpg, so yes, slower defiantly saves $. Very basic math shows I'll get more than 100 miles per tank if I ease up a bit (that's at 36 gal and not even looking at my current 46 gallon tank cap). Thing is, I just have sooo much trouble driving slow.

EMrider · 06-12-2009, 03:50 PM

Quote:

Originally Posted by Ed in Montana

As Skywagon knows from the Moab 4WD training, I drive slow in almost all conditions. On Interstate driving, I rarely go over 65mph, cause I don't like how the van handles at 75mph plus. Too much bouncing around. Perhaps with Deaver springs it would feel more stable. Also, in heavy traffic, the stopping distance approaches one light year at higher speeds. Defiinitely looking at a brake upgrade next year.

Still, the SMB is averaging 15.5-16mpg on the highway fully loaded. Several times driving 55mph it's gotten almost 18mpg. I was surprised that the van averaged 13.5mpg during the three day 4WD training in Moab, over some fairly rough country.

My feelings exactly. Never go more than 65mph and usually between 60-65mph. Don't feel safe going faster and I get too many vibes above 70mph. My MPG is consistently between 15 and 16.5 depending on whether or not I'm pushing a headwind.
Rob