To be Idling or Not to be Idling?

I went out to work on the Airstream in storage the other week. I typically pull the batteries during winter storage, but I didn’t this time because we were gonna take a quick winter trip (that didn’t pan out).  Actually, to be completely honest, I didn’t bother pulling the batts because I don’t get any more longevity out of them whether I go thru the hassle of storing them on a Guest 3-stage charger, or not.  To the Battery Guru’s who may be reading this: flame away.

I digress. So, the batts have been sitting, no maintenance charge, for about 2 months. I decided to back the E-350 up, plug in the 7-way umbilical, and let her idle to charge the batteries while I worked.

It idled for about 2 hours. All gauges were normal.  I’ve seen this van put as much as 15 amps back to the batteries- pretty good for tow vehicle trailer wiring.

Fast forward to my next fill up. The van is our daily driver, typically get between 16-18 MPG. Well, the “idling for 2 hours tank” came back with 13 MPG.  I was really surprised.

I know “idling” and “efficiency” when talking MPG is sort of an oxymoron, but I guess what I mean is I thought it wouldn’t burn as much fuel.  Stoichiometrics of diesel engines, and all…

After a little research that included a discussion with an actual diesel mechanic responsible for a fleet of 200 vehicles ranging from bulldozers to Class 8 trucks; it appears idling is not recommended.  “Wet stacking” being the primary reason.  This is a condition in the cylinders where due to lower combustion temps and incomplete burn, the fuel washes down cylinder walls and adds to fuel in the oil which in turn causes accelerated wear on all oil lubricated components.

So, for charging the batteries, it looks like a dedicated generator is best.  Besides, a Yamaha EF2400IS is much, much quieter than my E-350.

See you Down the Road!

“Gas Buddy” Challenge

Back from another successful, delightful vacation to Topsail Hill Preserve State Park and St. George Island State Park.  (See my earlier SGI post here)

‘Gas Buddy’ is a great website (and iPhone app) that gives you best pricing on fuel along your route, based on your range (and minimum gas tank level preference).

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“Gas Buddy” estimate

GB promised a $950.79 fuel bill, if we used the best priced stations along the route… this might actually be possible to do, if we weren’t traveling with a four month old.

The key to traveling with an infant is staying underway when the baby lets you stay underway (i.e. when the baby’s sleeping).

So, without any bargain hunting our actual expense came in at $1,136.61.  Hey, I’m not saying $186 is nothing.. but, if you were to try and put a value on happy travelers and peace of mind- it’d be a damn sight more than that.

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Check out the “carbon footprint”! But, don’t worry; I bought some “carbon off-set credits” from an online Nigerian prince representing Algore.
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GB can track your fillups, mileage, and MPG. The old girl did pretty decent at 7.9 MPG. Not bad for a 17,000+ pound rig.


Fuel Economy

Data export from “Gas Cubby” iPhone app


2005 Chevrolet Suburban 2500


8.1L (496ci)

3.73:1 differential

31′ Airstream Classic Limited Slide-out

Hensley Arrow 1400/14000

17,400 combined weight


Interestingly, when I remove the gas average of 13 and 10.9, because those numbers reflect (for the most part) an ‘unhitched’ ratio (while at Bryce Canyon), I get an overall MPG of 8.1

Return route

Total gas expenditure was $2,043.82 over 4,303 miles.

Start: Ruby’s Bryce Canyon, UT. End: Silverthorn, CO
Start: Silverthorn, CO. End: Dearborn, MI

The average speed was between 65 – 75 mph.

The overall driving fatigue was minimal.  Unlike when towing with a friction based hitch, where after 500 miles I felt thin… like butter scraped over too much bread.  This setup, is tuned perfectly, and gives me a ChrisMatthews tingly leg.  Between the Hensley Arrow, weight distribution, brakes, and of course bullet shaped Airstream, everything performs in harmony.  Even after our 710 mile leg between Breckenridge and Des Moines, I was ready for another two or three hours…