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Best Gas Mileage of all Motorhomes!


Bob W.

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Could you guys please repeat the math calculations again for me?

I'm not really sure on some of those figures.

Seems like I was just reading the (argument) postings, over and over for the last half an hour.

The best photo of all was the Asian dude "bicycling" his super tiny (non-motor)home. Now that is real MPG!

-Riverman77

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ugh Riverman77, are you just a magnet for controversy or are you trying to get Vincent and Maximilian to fight again? Nothing escapes the black hole.

the story was that I had great mileage going somewhere and horrible comming home. Somehow that became an argument. I lose. I have 0 interest in reviving it.

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Totem and Derek,

You both are correct! You guys got my point exactly!!

-Riverman77

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My normal mode of driving on long trips is to listen to an audible book and follow a semi-truck using the two second rule. This distance is about right to stay ahead of the two vortices coming off the top of the trailer. On a misty or rainy day you can see the vortices rotating, expanding and descending, looking like two cones off the top corners of the trailer.

On days with a severe headwind, the motorhome might be limited to 55 mph in max overdrive without drafting. With drafting, I can gain back about 10 mph. When I'm going fast 65-75, it is usually when I need to make a lot of miles. Normally, I like to find a truck in the 60 mph range, which seems to be the norm for most semi's.

On a sailboat, telltales are bits of yarn that show how air is flowing across the sail .For drafting, I look at the grass and trees by the shoulder to see how the semi is pulling the air along.

On a day with strong cross wind, drafting is useless to me so I stay further back 150 to 200 feet, and just let the truck be my guide. To me, it seems like I'm less fatigued when following a truck. The high speed traffic seem more inclined to pass me instead of sitting on my bumper - I can't go any faster than the semi, so sitting on my bumper isn't going to make me speed up.

A story on Car Talk had a quote from an aerodynamics expert. He basically said that there is a symbiosis between drafting vehicles. The vehicle out front benefits from reduced rear drag and the vehicle behind doesn't have to part the wind. Add a third vehicle and the mutual benefit increases.

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I'd advise against trying 'bump drafting' with an 18-wheeler.

A piece of (pretty useless) info from that Mythbusters graph (above) is that at 2ft fuel consumption actually increase vs 10ft. Gotta check sources and I'm afraid that the 'Made for TV' pseudoscience of Mythbusters isn't one of my favorite sources.

Thinking to myself, "I wonder why the chose 55MPH? Other than Toyota MHs, there aren't too many vehicles @ 55MPH."

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If you watched the Mythbusters episode, they explained that at two feet, Grant had to constantly adjust his speed and that was the reason the MPG went down.

Here in the states, there are a lot of trucks going 55 to 60 mph. Some of them have company installed governors. I once rented a 26 foot Hertz truck and it would not exceed 55 mph, even on a downhill slope.

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Thinking to myself, "I wonder why the chose 55MPH? Other than Toyota MHs, there aren't too many vehicles @ 55MPH."

Still on Jimmy Carter National speed-limit mentality maybe? My 1979 Datsun 280ZX has a Jimmy Carter speedo that only goes to 65 MPH. I've driven it well over a hundred and the needle hasn't bent or broke off yet.

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If you watched the Mythbusters episode, they explained that at two feet, Grant had to constantly adjust his speed and that was the reason the MPG went down.

Here in the states, there are a lot of trucks going 55 to 60 mph. Some of them have company installed governors. I once rented a 26 foot Hertz truck and it would not exceed 55 mph, even on a downhill slope.

No, haven't watched. Don't get Discovery Channel and dial-up rules out YouTube. Only read the onscreen write-up. I seem to recall there was a comment (written) about difficulty driving smoothly at 10FT.

Here all trucks have governors set at 105KPH (65.2MPH).

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There aren't many things where I'd be willing to self proclaim my expertise, but aerodynamics is one of them, I agree 100%. The only thing I would add, if you have your choice between lead or follow, lead. It takes less energy to split the air than it does to overcome the drag created by the air attempting to re-combine (all the turbulance that Skydancer described, very bad.

Anybody remember the Saab commercial many years ago where they showed turbulance of a truck and showed turbulance of their Saab car. We jokingly said the Truck had the same aerodynamic qualities as a McDonnel Douglas F-4 Phantom.

John Mc

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When cruising on a nuclear submarine on the surface, dolphins would swim in the bow wave, letting the energy of the boat help boost them along.

The air molecules in front of the camper are compressed, creating a positive pressure that helps push the semi trunk in front of me forward. The driver ought to appreciate the assist. I don't mind when folks get on my bumper, they're helping me get better gas mileage.

My Civic hybrid has two trip modes on its MPG meter. Besides instantaneous, which is displayed as a logarithmic bar chart, it indicates the average of the last trip. When I pull in behind a truck, the bar chart starts climbing to the 60 mpg area, then the trip meter begins to climb numerically.

The hybrid battery needs replacement so I'm down to about 44 MPG on average stop and go traffic. The civic has 150,000 miles on it and a new battery is about $3000. Not sure of the cost/benefit of replacing.

If I can find a junk yard battery, I could probably swap out the good battery sticks between the two. Cost would be about $600 plus the time of overhaul.

I've seen wrecked Prius parts for sale on Ebay. The overactive engineering side of my brain considered what I could do with a Prius battery in the motorhome. Take power off the drive shaft for a regenerative brake. Eliminate the engine alternator and take power off the hybrid battery like my Hybrid Civic.

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I remember years ago driving a Lincoln Continental with an instantaneous MPG readout. A first experience for me with such a 'toy'. With cruise set at around 60MPH, 18 wheelers would often come up behind me and pass. The MPG would stay pretty constant until they'd pull in front of me a couple of car lengths ahead. MPG would immediately jump a few MPG and then slowly drop off again as they pulled away from me. Can't say I noticed it increasing as they'd come up behind me, but I wasn't looking either. Next time I'm out in the Exploder I'll pay more attention but I don't drive it much where there are 18'wheelers in the mix.

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I've topped off the gas on my 21' sunrader 22r 4sp on friday night loaded with wife and 3 dogs (one being 80lbs chocolab). I manage to drive 108 miles averaging at about 60-65mph until i came up on another gas station, filled up the gas again and only 5.5 gallons until top-off!!! I almost peed in my pants. =)

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