Fuel Economy..?

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Hyperballsmcgee

Hyperballsmcgee

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before I start, I get distracted easily, so please bear with me if this is confusing. I'm also not sure if this is in the right forum or not.

currently I have a 340 Scamp that in building for the street and and annual or bi-annual trip to the strip, obviously being a semi-race car hot rod whatever-you-wanna-call-it it doesn't get too great of mileage, my daily driver is a 1999 ford ranger 4 cylinder 5 speed, $20-$25 gets me through the week, I feel more at home in older vehicles, my first car ever was a '74 ford maverick 200 i6 auto Trans that also only cost me $20-$25 a week to get around where I needed to go. to be honest, I think I was driving the maverick more than the ranger.

basically what I'm getting at is I've been considering trying to get my hands on a slant 6 car as a daily driver, so what kinda mpg's am I looking at in a slant car?
 
What the factory posted years back can be bettered with a few modern additions. Whe I won't suggest a F.I. Set up, I will suggest a MSD ignition to help get the most out of the air and fuel mix. With that in mind, pay close attention to the distributors curve and as well the carb to be used.

The gear ratio has a big play as well. The lower gear set (numerically) will give back good dividends when on the Hwy. Not so good around town. Keep within the engines peak torque area for best mileage since this area makes the most out of the fuel.

Exact mileage? No clue. Chrysler did have compitions with the other car companies across the nation to see who did best. They did post up some unbieveable reports. One fella from another board reported that his O.D. Manual trans 318 did better than 30mpg's.

If you /6 is in good shape, you could do very well.

Good luck.
 
Realistically you are looking at 20 mpg in town with a very good state of tune. There are factors that would improve upon this such as overdrive manual trans or a lockup auto trans.

Using a dollar figure as a comparison in fuel ecomony just plain doesn't work, unless you always buy fuel for the exact same price. I would not expect a 3.7 liter inline six with a carb to beat a 2.5l ranger that has better gearing, ignition, fuel control, and head design.

The best mpg highway I have ever heard from a reliable source for a slant was 27. Most claimed mpg from drivers is suspect. I have driven cars for customers for mpg complaints many times and I can usually beat the sticker figure. Read up on "hypermiling" those people are nuts but it shows just how much a driver can affect mpg numbers and why it is impossible to say just what mpg you will get.
 
If you were to get and learn to read a interior vacuum guage
you could pick up some mileage.
Probably one of the simplest/cheapest methods of saving gasoline.
 
My nice weather driver is a '72 /6 Scamp. I have a 26 mile round trip for work. When I drive it simply to work and back for a week, I average 18mpg. When I drive it on the highway for longer distances, I average 22mpg.

225 /6, electronic ignition, 2.25 exhaust, Holly single barrel carb.

There are many mpg threads here and at slantsix.org.

I get better miles per gallon when I drive my Honda. I get more smiles per gallon when I drive my Scamp!
:cheers:
 
longarm said:
If you were to get and learn to read a interior vacuum guage
you could pick up some mileage.
Probably one of the simplest/cheapest methods of saving gasoline.
Click to expand...

X2My daughter had a 1991 BMW 318is (1.8L = 110 cu inch) with a fuel economy gauge (vacuum). We drove out to Las Vegas (270 miles) for one of her volleyball tournaments. I decided to make the first leg of the trip while keeping the needle in the economy range for as much as possible. I got 48 mpg! I was able to run at 70 - 75 mph on the flats. On the return trip, I drove how I would normally drive and managed to get 32 mpg.
 
i daily drove a 72 dart with a cast crank 440 for almost 2 years and during that time i guzzled down a LOT of fuel. most the time i didnt check but the few times i did ....it was maybe around 10 to 12....ish...and my slant gets maybe around 13 to 15 ...ish the few times i checked it too.

i would tell myself that i would drive with a light foot and sip the gas on each one.....but then when i was on the road and the good feeling of taking off from red lights rapidly and feeling the power became too addictive i was a lead foot wanting to hear that thermoquad open and feel some real torque all the time even with the slant.

so unless your a total miser in every sense...asomeone who mises that much would be driving a prius.....dont BS yourself into thinking your going to drive with a light foot and sip the gas when you have a ton of torque under the hood begging to be unleashed.

BTW i followed the traffic rules and rarely broke the speed limit ....i just got to the speed limit a lot quicker than most.

be real ...if you have an engine with some real power your going to use it unless you have the will power of an ancient chinese monk. your in a mopar .....gas milage....whats that?
 
All of my/6'a were guzzlers. Everyone would bash me for not knowing what I'm doing, poke fun at my skills or lack there off, accuse me of not properly doing my math, short clicking the fuel pump, etc... The ragging went on and on by the /6 Internet hero brotherhood.

I suppose if the engine was a fresh one with mileage being sought after in the building of it, I really see no reason why it could not do well. How well is another story to be proven to me.
 
I have been driving the wife's 73 Dart, 4 door, 225 slant, with stock size radial tires, daily for the last month. My daily drive (round trip) is 74 miles, 95% highway, and I don't go over 60 mph.

Mods: Fuel line mod, timing at 6 btdc, plugs, cap and rotor as recommended on slantsix.org

My average mpg, calculated by tracking miles driven divided by the gallons on my fuel receipts is 23.7.
 
Back in the early to mid 70's I consistently got low 20's to as high as 25 mpg on a long trip. The car was a very plain 66 Coronet with a s6 and 3 on the tree, holley 1920. It was well worn, paid $360. That was back in the day of good gas, 75 mph speed limit, fewer stop lights. I lost a couple mpg when they dropped the speed limit to 55. I have always checked my milage at every fillup, good habit. Drive like you are in a hurry. Do not warm a car up.

Tricks for milage, taller air cleaner filter, CDI ignition, advance timing, 195 thermostat, perfect alignment, 60 series tires on the rear.
 
The mileage on my '71 Scamp (with a 225 six) varies depending on driving behaviour; with a heavy foot on the highway I've netted low 10s; if I mind the limit I can get almost 20 mpg.

I've yet to do a miles-versus-receipts overall average like 1968FormulaS340, but when I do I'll let you know what I find.
 
I got a heavy foot but out of the dozen /6 car ive own never found any if them to be great or really any better then any 318 car ive owned, but really most real cars (non econo box's) get city 15-25 mpg, with proper driving and some tuning you should be able to get city 18-20 mpg /6 or 318. Even super fuel efficient cars only get 25-35 in town mainly cause of there weight.
 
I kept careful records in my 69 Dart 225 for years. Averaged 21.5 mpg hwy. That was mostly back in the 55 mph speed limit days. The last 3 years I had it, I had a Crane XR700 electronic ignition, but don't recall the mileage improving noticeably. The Holley 1920 always idled lean, not sure about higher rpm but the plugs were always light grey.

Maybe the best addition for tuning would be an oxygen sensor monitor. Wideband are best, but expensive. I got a few simple lean/rich indicators (MSD or Holley) on ebay for ~$25 (list ~$175). Even cheaper, I got some surplus kits intended for Onan generators, which includes sensor, bung, wires, indicator box. Only problem is ~30 sec filter makes it hard to tell cause/effect when I adjusted my Holley Pro-jection. Not much an issue for monitoring a carburetor in steady driving. You could even jet the carb slightly rich and plumb a vacuum line to the cabin w/ a little valve to lean it out per the O2 sensor. One company planned to sell that approach (automated feedback) back in the 1990's.
 
I have a 77 d200 crew cab pickup with the optional heavy duty frame, slant six, auto trans. The Army ran it till they decided it was worn out, then it went through at least 3 businesses and 3 individuals before I got it. No sign the engine had ever been opened up, ever, and I was able to get a best of 17 mpg hwy. I never adjusted the valves, set the timing, tuned the carb., or even replaced the plugs. I averaged ~14 hwy/10-11 city in that beast and never lacked power to make things move! In a car you should have no problem getting decent mpg. Just my experience, your results may vary.
 
On my extremely worn 72 I get 21mpg on the gas... and 400mpg on the oil...
 
My 71 Scamp is my daily driver. Literally the only one of my 3 cars that I really enjoy driving. Its a super six 2bbl set up with the Protronix Ignitor 2 with the Flamethrower coil electronic ignition. I get about 18mpg combined (with a heavy foot and doing 75 on the highway) i got worse gas milage when it was the 1bbl carb even with the electronic ignition. Averaged about 15mpg but i could never get it tuned right and the choke didn't open the way it should have. Also its cold where I am. Personal experience you'll get around 18 mpg (all 3 of my driver slants were right around there)
 
If I may make a suggestion......hope for the best but expect the worst....I have not driven a / car since the early 2000's and it was well worn....all the way around. Was lucky to see a combined 11 mpg out of it, driving with a very light foot.
 
We should put up a slantsucks.org. Mine got 16-18 good day, the 360 gets the same and has 250 more HP.
 
The milage on a slat six car can vary widely. Depending on the condition of the engine, the type of car, and the type of driving. In general a slant car in good condition will get about upper teens average. A heavy car in poor condition/tune will get much worse. I have a 64 Valiant with a fresh engine, built for economy, with a 3 speed standard trans, that gets upper 20's mph on the interstate.

PS: a MSD ignition on a near stock slant is a waste of money, if you need to convert from points, a HEI is more cost effective.
 
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