I have an 82' Dodge 150 Van that is camperized with a slant six of course. I am trying to find ways of improving the Mileage. Is there any additives that work? Does larger exhaust help much ( worth the change over?) Any suggestions would be really appreciated.

Hello,

Additives DO NOT work. (In fact, I just saw a report that in 20+ years of testing additives, magnets, air-swirlers, and other gizmos, the consumer agencies have never found anything that increases your mileage by 1 full mpg!)

Headers may help... perhaps a camshaft producing more lower-end torque might help.

What are your driving habits now (city vs short trips vs long trips)?
What is your current MPG?

Don't forget the basics:
-Complete Tune-up, (plugs, air filter, timing, etc)
-Proper pressure in all tires
-Drive like you have an egg under the gas pedal.

You have a heavy vehicle, mileage may be tough to come by...

-Mac

Hey Slanted Opinion,

Could you show me that report? Just curious, as I like to collect stuff like that on my blog.

_________________
"Mad Scientist" Matt Cramer
'66 Dart - turbocharged 225
My blog - Mad Scientist Matt's Lair

Sorry Matt, I saw the report on television, one of the evening news reports, like 60 Minutes or Frontline. I don't have a reference to give you. But I do specifically remember that they tested pills for your fuel tank, "Tornado" type air swirlers for your intake, special air filters, magnets on the fuel line, and oil additives. I believe one of the additives for the fuel did result in a 3/10 of 1 mpg increase, but the cost of the additive completely negated any savings at the pump.

For the most part, I think that engines made in this century are so darn efficient right from the factory (hp per cid) that there is very little to be done to increase fuel economy. Heck, the new Hemi Charger is supposed to get something like 25 MPG by freewheeling certain cylinders when they are not needed.

The slant, built on late 50's technology, should have some wiggle room for improvement, though. But will a slant 6 be able to deliver decent mileage in a camper-truck application???? Seems like your foot would have to be pretty well in it to get it down the road, hence low mpg. Maybe a 4-speed would help.

-Mac

Ok, thanks. If you remember anything else, like what group did the testing, let me know.

The biggest room for improvement (other than somehow getting modern combustion chamber design in there) may be fuel injection, but that isn't cheap at all.

_________________
"Mad Scientist" Matt Cramer
'66 Dart - turbocharged 225
My blog - Mad Scientist Matt's Lair

_________________

How about water injection? I have seen articles, and talked to people who swaer by it. WWII fighter plane engines were equiped with it because it helped them fly further to provide aircover for bombers. I' never applied water injection, but there must be something to it. Modern water injection kits are expensive and computer controled, but the old fashined ones simply sucked water out of a bottle into a vacuum line. Of course the bottle had to be below the carb inlet, or you would start a syphon effect that would fill the engine with water.

_________________

You said 'camperized'. The best way to improve milage is get a bigger engine, a 318 for example. Im sorry, but if your carrying a load like that around all the time, the cards are already against you. The slant will punish you at the pumps for making it a mule. Smaller engines ARE NOT better on mileage when it comes to pulling alot of weight. My 85' was also 'camperized' until I gutted it of 500lbs of crap and still doesn't get the mileage my suburban got with a 350! although it weighs half as much as the suburban.

This is only true if you're smaller engine is running with a rich power mixture and the larger engine can pull the load without the rich mixture. To put it another way if the slant is driving around with the power valve open or the on the rich step of the metering rods it is possible to get worse mileage than a 318 that can pull the load on the lean cruise mixture. This is the same reason why lower (numerically) gears often don't help increase gas mileage in heavy vehicles and/or ones with a lot of aerodynamic drag. The lower engine RPM requires a wider throttle opening and the engine no longer is operating on the economical cruise mixture. It has been shown, however, that more of a lean mixture provides better economy than a rich mixture. The reason for that is mostly due to reduced pumping losses.

If you want better economy reduce weight and drag. Make sure all the mechanicals including the chassis are tip-top and drive sensibly.

_________________
Joshua

The methanol-water injection system was used to mainly increase horsepower. The Germans used it in the early versions of the Focke Wulf 190 fighter plane until they came up with the GM-1 nitrous oxide system. The G-K variants of the Messerschmit Bf-109 fighter plane also used it. It gave a significant increase in horseoower but used a set of plugs every time it was activated.

The only reason they used it was because they lacked an effective turbocharging system. It was mainly needed to try and compete with turbocharged allied fighters.

_________________
82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

Most modern applications, the way I understand it, actually use the water/methanol to lower combustion chamber temperatures in order to reduce pre-ignition.

_________________
Used to own:
'82 Dodge D150
Erson 270 Cam, O/S valves, mild port work, ~9.5:1 compression

Currently fighting with an '85 VW Cabriolet

My other passion

Yes, Buick used that on their turbocharged 215 V-8 in the 60's. It had a little tank that held a water/alcohol mix (I think?) and was used to prevent preignition. But most people let the little tank run dry and engine would knock and detonate until it killed itself. Most of the turbo 215s were converted back to natural aspiration by the dealers.

_________________
82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

If you do a web search for water injection, you will find tons of stories by guys who claim to have dramticaly improved mileage for their naturally aspirated older cars and trucks. It just seems like there must be something to it. If you run water injection, then you can advance the timing more without preignition, and cruise at advanced timing. That would give you more MPG's. Just trying to be open here, and maybe get an enlightened debate going. Anyway, do the search, and you will see what I mean. This has been on the back of mnd for years. It's cheap, and might help. With a turbo car, you must use a system with a pump, or you blow the water out of the system under boost. That is why I haven't tried it on my car. I could buy an expensive commercial system, but I have other priorities for the slant before that comes up.

_________________

Water allows more spark advance, higher water temperature and leaner mixture - all good for mileage.

_________________

Is there a water injection system for naturally aspirated engines? All that I could find inject water in relation to boost...

VM