1967 Dodge Camper Special - gas mileage !

[Cageman]

what are you using for an over drive? I picked up a brownie box for my project, and it doesnt have a speedo hookup.

[RussRoth]

I have an Advance Adapter OD/gear splitter. It pilots into the bell housing and the tranny pilots into the back of the OD. Unfortunately AA refused to build one to fit any Dodge tranny. They gave me a choice of using a Ford or GM. I spent about 6 months calling and begging them to make it fit a Dodge but no go. I finally relented and went with a married SM465/205. Works pretty well but I like the 435's better. My speedo goes in the output section of the 205 although I did have to change the gear to correct the reading. Nearly got a ticket over that.

[PwrWgnDrvr]

Russ, u forgot to mention that it is NOT a 318 u are getting that great mileage with.

[RussRoth]

Russ, u forgot to mention that it is NOT a 318 u are getting that great mileage with.

Is that important???? I have 450 CID. .030 over 400 block w/440 crank and rods, KB 280 pistons. True calculated 9.5 compression. 452 heads CC'd and pocket ported. Cam is a Comp Xtreme 4x4, 218/226 @ .050. Runs every bit is good as I had hoped for and revs like I remember my 340 revving.

My cousin runs the machine shop @ High Desert Automotive in Bend, OR and they did all the machine work. Loren and I assembled and measured everything after hours. He asked me what I was looking for and I told him decent idle and bottom end because it is my hunting and (was) towing rig. And I would like to see about 350 honest flywheel horsepower and as much torque as we can get. He just got a big grin and said that will be easy. I believe that was more than accomplished. I had some things I needed to work on tuning better which is what I did recently. Still need to make a bit of improvement but can't yet make those changes. Runs better than ever and will be even more improved after I can get the additional change accomplished.

BTW, I couldn't get that 15 on a regular basis but I believe I can the in town 11. I think I can perhaps do 15 now on a 55 mph drive on a fairly regular basis. The in town mileage was not as closely done as I would like. I have a way to check it that should be pretty accurate. My town driving is not a light every block. It's almost 3 miles of 50 mph to the first light and spread out after that. I try to go when traffic is lighter and I drive for mileage, well most of the time.

[mattoxgolf]

Thank you all again for the messages !

I will say something without much reflection :

Is it possible to change my entire D200 Dana rear end for a D100 rear end that will open up the possibilities to change to a much higher rear axle ratio , I have seen posted here as high as 2.94 ?

It seems to me that if fuel efficiency is the word of the day, I must increase my rear end ratio and install a transmission with overdrive, look into fuel efficient tires, have a carburator dialed in and Basta !!!

[712edf]

Thank you all again for the messages !

I will say something without much reflection :

Is it possible to change my entire D200 Dana rear end for a D100 rear end that will open up the possibilities to change to a much higher rear axle ratio , I have seen posted here as high as 2.94 ?

It seems to me that if fuel efficiency is the word of the day, I must increase my rear end ratio and install a transmission with overdrive, look into fuel efficient tires, have a carburator dialed in and Basta !!!

Technically yes, but then you'd have 5 lug wheels on the back only. Things like axle swaps, OD transmissions,tires, FI set-ups,etc can be expensive & may take years of driving to pay off their initial costs.

If it was me, first I'd have a perfectly working carb. Second I'd keep speed (rpms) down (drive slower, yes this sucks). Third I'd be on the lookout for Dana 60 3:54 set-up (was a car option, so has aftermarket support).

Tires & OD are great too. The OD sounds like it'd be costly unless you run across somebody selling a used one.

Bucky

[712edf]

For the record, my 2004 chevy astrovan (another aerodynamic brick) with modern fuel injection, V6, OD trans & higher gears doesn't even get 18mpg on the highway, not at 70mph anyways.


Bucky

[soopernaut]

I just wrote my reply but Bucky's reply caused mine to not go through and I lost it so now I'm re-typing.

Yes on the rear axle swap. You will have a different bolt pattern and possibly a different sized u joint.

You probably don't want a 2.94 ratio if you are running a overdrive auto. The factory never put anything higher than 3.55 behind the od auto but I don't know if it was so they could keep the towing capacity or to keep the engine in the powerband.

There was a 3.07 Dana for the Diesel trucks only.

[digdoug]

Max,
I hate to throw water on your fire,but as many have stated,it would make the best sense to just get your truck in good tune and drive it when you need a truck. Changeing gears or doing a OD tranny will not give you ANY better mileage without swapping cams and retuneing your engine,at this point your truck will be wore out before payoff.

I have a truck that I bought cheap, only do maintanance on ,it has 4.88 gears and has a top speed of 55. The best milage I have gotten from it is 13 mpg.

I have another truck that I have put thousands into. It has 4.10 gears ,overdrive and will go faster than any sane person would want to go. The best milage I have gotten from it is 10mpg.

I always feel smarter when I am driveing the slow truck.

Dont let it set,putter on it and enjoy driveing it on weekends.

[OregonDodgeboy]

... Things like axle swaps, OD transmissions,tires, FI set-ups,etc can be expensive & may take years of driving to pay off their initial costs.

Here's my thoughts, as I have contemplated for a while these very same concerns:

Driving as many miles as he will be driving, I'd bet that the cost would be recouped rather quickly. The GM EFI can be very affordable. If you can do alot of the work yourself and get the parts cheap, (my first setup was given to me), it would be even better. All the Scout guys I know that have converted their rigs to the GM EFI report going from 10 to 15 mpg average before tuning the chip, and an easy 18 once tuned. (One said he could probably get over 18 if he could "just keep my foot out of it". Huge giggle factor there ) So if a guy spent, say, $500 total for the EFI, including tuning, and his milage was 15 mpg vs. 10, I don't think it would be long to recoup.

The axle swap is next on the cost list, but an easy swap if you replace the whole unit. Regearing isn't hard, but not everyone can do it. So if you must take it to a shop to do, get a few quotes from reputable shops before you spend. Dad had his 86 D200 re-geared from 4.10's to 3.54's in 1992 and it wasn't cheap. We were hosed a bit on labor I think, but it was a quality job. I'll ask him today what his milage change was, but it went from screaming along at 60 to loafing along at 75.

Overdrive transmissions are highest on this list for several reasons. First, they cost more just to buy one, much less rebuild one if it needs it. And if you get a good deal on one, it probably does. Unless you know someone and can get a good deal. Then you are making and adapting things, which adds to it. Possible new crossmember, likely a shortened driveline, etc. With the OD trans, you can leave the rear end alone though. That's a plus. And there's no chip tuning like on the EFI.

If it was me, first I'd have a perfectly working carb. Second I'd keep speed (rpms) down (drive slower, yes this sucks).

Bucky

True, you can get alot from a good tune on the carb and ignition. Also, learning smooth and steady driving habits help. I got 12 city/highway with my 66, and that was with a 440. And had I tuned it better, it would have been even more I believe.

[712edf]

I just wrote my reply but Bucky's reply caused mine to not go through and I lost it so now I'm re-typing.

Sorry about that:(

[rogerr]

A diesel will get better mileage but only with the right gears. Diesel conversions get expensive fast.

My advice, get a magnum EFI 318 and the OD automatic with it if you want a mileage swap, even so, don't expect miracles.

The wiring gets complicated but it can be done.

In no case will you get the kind of mileage a little FWD fuel injected four cylinder car will give you. isn't possible.

[67cspowerwagon]

well here my 2 cents A518 . good front end alignmet and some Hwy truck street tires with the right air in them and a good ture and put amsoil in the trans and rear end 354 dana's would me nice have looked and seen what you have I have a CS 318 727 354 sg dana 60 well that my two and a hlf cents LOL

[40YearOldFury]

Thanks again for all of the replies !

This site is fantastic for me, I will definitely be keeping an eye out for great ideas...

I am beginning to think that my best chance of really improving mileage is to install a different center pumpkin in my rear end, I have been proposed a 3.23:1 and in addition, I could change over to an A 518 transmission. I read that this transmission could improve up to 30% of gas mileage compared to the A 727. I know that this is going to cost me, but gasoline could be over 4 dollars soon and If I drive over 400 miles a week, it will quickly pay for itself.

I will do a little research on the best tires ( size and tread ) for gas mileage and will just change over to something more meaty in the winter...

Also, if I am going to have to change my entire brake system after so many years, is it possible / worthwhile to try and go for disk brakes, at least in the front ?

Thank you all again !
Clint

I just completed my a518 conversion in my 65 with a 318 and am up to 14.6 mpg, I was getting 10mpg before the conversion. I also have 4.10 gears like you. I drive about 50 miles a day to and from work. I am still tuning the transmission OD/LU points but hope to get it up to the 18mpg mark. I am running LT235/85r16 tires that are close to the factory size on my truck.
Not a bad conversion on a small block and if you have an auto now you have all the linkage, shifter and stuff you will need. There is a kit out there for $85 I think you looked at from PATC. Check out my build thread, there is a little more information in there. I am pleased with how it operates and the ROI of the project. The conversion took me about 2 weeks of downtime on the truck, but I had other personal things going too. The actual putting the transmission in was a 1 day deal. Planning is key. Next I will be installing a Holley Projection I found on Craigslist for $75. Hit me up with any questions!

[DukePW]

Hands down the best milage you can get is not to drive it

Seriously, if you have a 90mile a day commute find a cheap vehicle to make that trip or keep using the same mode of transporation you have now. Tinker with your truck to get it running and street legal, then do mods when you get the chance. Keep the truck as a criuser and the odd run to the hardware store ect.

[soopernaut]

I still thing it would be cheaper to use one vehicle for everything. Even if you don't get the best fuel mileage you still have a long way to go before another vehicle is going to save you money.

[DukePW]

Maybe but by the sounds of it, sounds like he already has another mode of transportation, if he gets the pickup runnin its icing on the cake

[RussRoth]

I finally was able to do an accurate mileage check. I can run my rear tank completely empty consistently as long as I am on reasonably flat ground. I ran it empty and put exactly 5 gallons in it. Set my trip odometer to 0 and ran on that tank until it ran dry again. It is about as accurate as I can get. 55.8 miles. This was not even my normal town type driving. Considerably more around the block and stop light driving than I normally do. No freeway at all. Just worked out that way but I am fairly happy with the result under the circumstances. I do have to check the accuracy of my odometer again but as I recall it should read about 1% more than it does. I'm not going to mess with it much more right now as it runs very well and hunting season is right on the horizon. I do think there is even a bit more that can be wrung out of her.

[Pawpaw]

Loaded or unloaded, 13mpg, uphill, downhill, headwind, tailwind. 12 w/ the hubs locked. This was the same for my 74 Power Ram Charger or my 71 Power wagon. Nowadays, we only start the truck if we gotta pull down a tree or haul manure and then only if we have found the parts we need to keep it goin.
Love my truck though.
Gary

[WD]

69 D100 with a 318/727 and 3.54s got a whopping 8-10 mpg moving from Seattle to Memphis this spring. With a horse trailer behind it. A VERY aerodynamic same era horse trailer with 4 bales of hay and a miniature horse in it (so about 500# more than the empty weight). LT235/75R15 Canyon Climber tires on all 4 corners.

Take a cinder block and put it on an old style metal roller skate. Put 2 packs of smokes at roughly cab position. There are your aerodynamics.

318 is a good little engine. And a 4bbl carb can seriously help the fuel economy.

Mine hasn't been off farm since we got here. I commute and haul my work tools in a 2.3L 5spd Ranger that even with issues gets 23.5 mpg. My 49 got better fuel economy than my Swepty.

I love my Sweptline but even with our combined income of $100 an hour, it doesn't make sense to drive it much.