Gas Mileage 318

[AC-Craig]

Sent: 8/26/2002

I put 379 miles on my D22 w/ 318 this weekend. got between 8.8 and 7.5 miles/gallon. does this sound normal?
I was hoping for closer to 9-10 mpg.

AC-Craig

[Derrek]

Sent: 8/26/2002

AC-Craig
I have a D22 with the 318 and after several trips the longest so far being 500mi, I am getting around 7.5mpg and just like you I was quite disappointed.

I purchased the motorhome several months ago and it already had been upgraded with the edelbrock intake and carb and a dual exhaust so my expectations were high.The guy I bought it from must also have been high because he said he could get 12mpg while towing a car!! HA! HA! Must have been going down a really steep hill.  I have checked the position of the choke (manual choke) and it is fine. I also removed several spark plugs and it appears to be firing normal. 

I am very pleased with power and how engine runs overall but fuel mileage is not what I expected, but when you factor in the added comfort and the savings on hotel rooms I guess I can't complain.I am a NASCAR fan and this weekend I am going to Darlington and then spending a week in Myrtle Beach.  The entire trip will be approx.1200mi so I can give you a fuel mileage update when I get back.  Not expecting much difference.  Hope this helps

[AC-Craig]

 
Sent: 8/26/2002

Derrek,
Thanks for the response. My D22 still has the standard 2 bbl carb and stock exhaust. Power is lacking going up a good hill with nothing in tow, but it runs great. If going with the 4 bbl and dual exhaust will give me more power and about the same mileage, the upgrade is looking better and better.  AC-Craig

[jvf]

Sent: 8/27/2002


AC- I just made a 2400 mile trip in my D22 and averaged 9 and did actually get over 10 a couple of checks.  I have the stock manifold and 2 barrel.  I do have a new exhaust system and have changed over to electronic ignition.  If your is older than a 73 you might go for the ignition upgrade and a high voltage coil.

Jim
72 Indian D22

[Derrek]

Sent: 9/10/2002

AC-Craig
   I just got back from my trip. Traveled about 1500 miles and for the entire trip I averaged 7.5 mpg.

So for the time being I guess that this is normal. I would like some more info on the ignition upgrade that Jim spoke of in his response. I did find one thing to be unusual though, whenever I was going through the mountains or the engine was under a heavy load and the engine temp would start to increase it also seemed as thought the gas mileage would also increase. The guy who owned the motorhome before me and claimed to get 12 mpg towed a car and I do not.I am wondering whether he may have put a lower thermostat in to compensate for the added load on the engine and now that I am not towing maybe the engine is running too cold. I know that 12 mpg is a fantasy but every little bit helps. Does anyone else have any ideas?

[Derrek]

Sent: 9/11/2002

In the message I posted yesterday I forgot to include so info I found to be helpful.I have seen questions posted about how to determine fuel tank size and was wondering how to do this myself. The original manual for my motorhome says that the main tank is supposed to be 25gal and does not say anything about the aux tank.I measured the tanks and entered the dimensions into the rectangular tank calculator at www.greertank.com/tankcalc.htm and determined that both tanks are 40 gal.

[denisondc]

Sent: 9/11/2002

     The slower you got and the flatter the terrain the better your mileage.  I like to go at the same speed as the truckers or a little slower, so I ain't in their way much, but don't have to plan on passing either.  I get 7.5 to 8, travelling at 55 to 60.
    Make sure the outer distributor shaft, (the one with the rotor on it) springs back when you twist it to the advance position.  There is a piece of felt under the rotor at the top of the distributor shaft that needs to be oiled, or it will stick and lower your mileage.  Good luck.     Denison

[Derrek]

Sent: 9/12/2002

What you are saying about the mileage is logical and what a person would expect but in my situation it seemed to be opposite. I averaged approx 7.5mpg for the overall trip but my lowest reading was 7.1mpg traveling between Virginia and South Carolina (mostly flat ground) and my highest average was 8.3 traveling from Ohio to Virginia (mountains) Go figure?! I have also not ruled out the fact that these calculations may not be 100% accurate based on wether or not I am getting the same amount of fuel in the tanks each time. But it is safe to say that it is fairly close. I also agree with traveling at 55-60 that is plenty fast for one of these old rigs and it is nice to just blend in with the semi's. Thanks for the tip on the distributor I will check that.

[Stovepipe]

   
Sent: 9/19/2002

AC-Craig, I have a 73 Brave w/318 and recently went out to Colorado on vacation and we averaged 8.5 MPG.

I had the same concerns as you when I first got the mh. When I first got our mh I was getting 5.5 - 6.5 MPG. After many hours of tinkering, cussing, and consulting with others, I have learned to accept it and just enjoy the mh. The thing that made the most difference was dropping the gas tank and having it resealed. There was rust in it before and was clogging up the fuel system. I also replaced the original carb with a new rebuilt one. I had rebuilt the old carb so many times the upper plate was warped and wasn't getting a good seal. Also, remember, the big flat face of your mh pushes alot of air, if its windy at all, it will make a difference in MPG. Good luck!   KEVIN

[jipjob]

Sent: 10/29/2003


I've have read here that most people get anywhere around 7 MPG but I think their was one person here that was getting 9 MPG but he had done a lot to his engine to get this. What was interesting to me in one of these messages, one person describes our rigs is like moving down the road with two sheets of plyboard on the front.  jipjob

[kevsws6]

Sent: 10/29/2003

When I had the original 318 in my rig we averaged 9 MPG. I can still get that with the big block. With more power you get up to speed faster and climb hills faster cause you can. So that eats up more gas.

I got a solid 9.5 out of my last trip. That's cause dad was with me and I drive slow and cautious with him.

[Beatty1950]

Sent: 11/21/2004

Well ... I topped of MISSTANK's fuel yesterday.  It has been awhile so don't know if I had done a top off without clearing the ODOMETER Trip guage.

Is it reasonable to think that my MPG was 14 MPG ??  My Wanderlodge is getting 8 MPG.  Significant difference ...   But 17 ton vs 5 ton will do that to your MPG.

What MPG have other Winnebago owners seen

Dave Beatty

[denisondc]

Sent: 11/21/2004

With my 72 D22, weighing 5 tons, I get nearly 8 mpg if everything is okay. My C20 step van with a 250 cubic inch six would get 12 mpg if I kept below the speed limit. My 87 chev conversion van with a 350 gets 13 or 14 mpg. I do most of my mileage calculations based on emptying and refilling the vehicles fuel tanks at least 5 times - to make the refilling errors smaller.

[LJ-TJ]

Sent: 11/21/2004

L.J. and I are getting ready for one more little hope before we put up for the winter so in about 10 to 14 days I'll let you know how we made out. However on your last trip out we averaged 7 to 8 in our 318 - 21 footer.

[Beatty1950]

Sent: 11/22/2004

Well ... Thanks for all the input on a reasonable MPG for a 318 D19.  It appears I must have forgotten to push the button on the Speedometer when I fueled up or I have the best MPG (14+) in the known Classic Winnebago World.

It is amazing that the 8 MPG is the same for my 17 Ton 35 ft BlueBird as the 5 Ton 19 ft Winnebago.  I guess that shows an advantage of the 636 Cubic Inch Cat Diesel engine.  But then again my LOF (Lube Oil Filter) for the Wanderlodge (Engine and Generator) cost me $500 including some minor extras done.

Dave Beatty

[Derrek]

   
Sent: 11/22/2004

Dave

The fuel mileage difference is not all that amazing to me. I put 5,000 miles on my 1973 D-20 Brave powered by a 318. I never towed a car with my Winnebago and averaged 7 mpg. I sold the Winnebago and purchased a 78 Apollo 33' built on the Dodge M600 chassis powered by a 440. It weighs slightly under 16,000lbs and I have always towed a car with it. My average mpg is still 7. I really have no explaination for this, but I certainly am not complaining....

I know that you are probably just joking, but if you are in a position to keep your Winnebago, you may want to seriously consider doing so.

Numerous times I have had friends and co-workers hint around about renting my motor home. They would like to have their own motor home, but either don't have anywhere to keep it, or don't have the mechanical skills and tools to maintain a motor home. Renting out the motor home that I use and have my stuff in is totally out of the question, but if I still had the Winnebago, I could lend it out to close friends and relatives for a small fee to cover the cost of upkeep, plates, and insurance and it would be a win, win for everyone involved. Just a thought......

[Slantsixness]

Sent: 11/23/2004

I get almost 14 MPG down hill with the engine off! But actually Smurfbago ('72 brave D20RG / 318-3) does get 10 MPG on reasonably flat surface and at no more than 60mph. Slow, but at above 60, the mileage goes down to 8MPG real fast.
Take your time, keep your foot out of them, and they'll still have gas left when you go by the first gas pump! It's the second gas pump that'll get you!

As far as renting out a MH, all I can say is INSURANCE, Cleanup and Maintenence. I "loaned" my old Dodge Xplorer to  "freinds". Came home supposedly "cleaned" with a broken water heater, full black tank, torn gaucho cushion, and mud and leaves all over the floor. Not to mention empty propane tank, and a quart low on oil. I'm a forgiving person but I won't ever do that again. They even convinced me that they knew how to use a MH. And asked me if they could use it again 6 months after... What a nightmare!
They did pay for the water heater, and finally bought their own MH (some crummy Jamboree with a leaky roof). We got Smurfbago this August after I sold the Class B in June.

Just a thought...
Slantsixness
(Tom)

[Gmil031]

Sent: 3/14/2005

I have a 1972 D20T with a 318-3. I get 9 mpg. On my stock air cleaner housing, I turned the top upside down. It lets in more air. I also made an air-dam for below the front bumper. I made the air-dam from a 1x12 piece of shelving wood. It angles back from the bumper at about 45 degrees, like a windshield for the bottom. These are easy low cost tricks that I believe help the MPG and the air-dam helps make the ride more stable.

[LJ-TJ]

Sent: 7/25/2006

Hey Guys,

        L.J. and I traveled 668 miles round trip and burned 79.3 U.S. gallons which works out to 8.42 miles to the U.S. gallon. Average cost per gallon was $2.99, which works out to $237.00 or 35 cents per mile.

[angrybreadbox73]

  also if us soo inclined i would checkout a hydrogen generator to plumb into the intake to boost mpg

[ibdilbert01]

My 340 averaged about 9mpg going through the Allegheny Mountains in the PA/MD area.   I didn't think that was too bad but I also took it easy on the old gal. 

[LJ-TJ]

Just got back from a trip on  a machine shop rebuild on my stock 318. With me driving (old lead foot) I got 8 to 10 miles to the gallon at 60-65 mph. With the wife driving 55-60 she got between 10 and 15 mph.

[Jrcuss]

Just ran up to Quebec from Maine and covered close to 500 miles. We averaged 9 mpg  we took the back roads and cruised at 35-50 mph most of the way.  I was pleased as I was expecting 7mpg.
James

[mike roy]

has anybody tried a fuel vaporizor with a heated canister to help the fuel vaporize before the intake manifold?

[ibdilbert01]

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