Fuel mileage dropping

[AMC Diplomat]

Yea, it’s so bad around, Chicago that you can find plenty of stolen Mopar shit on Fb Marketplace. They don’t even try to hide it in their post.

Yeah because only half the homicides in Chicago get solved, and of that solved half, only half of those lead to charges. Chicago is 2 steps from being an anarchist's wet dream.

Man I feel lucky. The 'burb I live in, especially the part of it my house is in, don't have to worry about theft (or any crime)much, if at all. You could leave a car parked at the end of the driveway, keys, title and $100 bill on the dash, with the lawn mower and snowblower next to it, come back a week later and 99.9% probability it would all be as you left it, untouched. I mean, not going to do it but could with very little worry. It's the way it should be.

That's what criminals call a target rich environment

 

[Aspen500]

Trying to figure out how to say this without getting political. Let's just say all these big, crime ridden cities like Chicago, Milwaukee, NYC, L.A., Portland, Baltimore, San Fransisco, etc....all have one thing in common and leave it at that.

 

[Yellowdart]

How bad are things in North Carolina? What is going on down there? I always loved it there.

 

[PursuitSpecial]

Well, we caught the jackasses who stole our cars and it's a very complicated story... the short version is that they came back to steal more and we caught the rollback driver, he claimed he was legit and was working for this other dude who told him the cars were his and wanted them crushed for scrap. Of course he's probably in on it but the investigation is pending. The absolute IDIOTS have crushed them all for scrap, all that good sheet metal, brake and suspension parts, trim, glass, 2 383 engines and 727 transmissions, all gone. The police are investigating, we have all their license plates and info but who knows if it's legit and will lead them anywhere... the cops were right there with them but had to let them go, they'll probably never be caught. I just can't get over how big of a waste it is... I'd at least feel better if the parts were being used for something.

 

[Justwondering]

put a lien on their assets (homes, cars, etc) for the value of the parts if they were sold not scrapped.

They will have to clear your lien to sell whatever asset they have.

JW

 

[Mikes5thAve]

And the guilty get away to do it again. They should have nailed the guy who came back. If he had proof he was legitimately innocent he should have been able to give someone else up. Where was he taking the cars? Who's getting the money? He knows something.

 

[PursuitSpecial]

On the topic of fuel mileage, now that I'm parking my car in a safer location and putting premium ethanol free gas in it the mileage has like stupidly improved, I'm getting over 21 mpg driving to work now, not even on the highway. I went to top it up the other day after a month of driving and couldn't believe how little fuel it took to fill. I wonder if it's the fuel improving it that much or if people have been siphoning my gas since I started driving it? It would probably be even higher if it still had the lockup converter in it, it failed a few years ago by sticking in lockup mode and my grandpa had it replaced with a non lockup 904. Do you think it would be worth rebuilding the original one? Also an update on the situation, we keep having trouble with people trespassing, and it turns out there's a ton of drug activity in the housing complexes around here so that explains the constant thefts. The police know and can't do much, they raid the place and make arrests and new people just come to fill their place.

 

[Cordoba1]

May I ask why you are putting premium in your car? If you are running stock compression, you may be dumping money down the drain. There is a lot of mis-information about what premium fuel is. It is literally harder to ignite and burn than lower octane fuels. All things being equal (on standard-compression engines), premium isn't likely to improve performance, nor will it improve fuel economy. Premium fuel has the same energy content as regular. Source: AAA et. al. Don't Confuse Gasoline Octane And Quality

 

[AMC Diplomat]

May I ask why you are putting premium in your car? If you are running stock compression, you may be dumping money down the drain. There is a lot of mis-information about what premium fuel is. It is literally harder to ignite and burn than lower octane fuels. All things being equal (on standard-compression engines), premium isn't likely to improve performance, nor will it improve fuel economy. Premium fuel has the same energy content as regular. Source: AAA et. al. Don't Confuse Gasoline Octane And Quality

Idk about the original poster, but I use 91 ethanol free because the owners manual calls for 91 and it's also easy to find Ethanol free. All the ethanol free grades I see are 90 and 91, occasionally 93.

 

[PursuitSpecial]

I was experimenting to see if it affects the mileage, and it does. Even my stock slant 6 is getting 3-4 mpg better on premium than regular, which does sound like a lot but the extra cost more or less balances out the gain. The best thing to buy is ethanol free gas, regardless of octane, which doesn't corrode the fuel system and you automatically get better mileage because ethanol burns richer than gas.

 

[78VOLAREWAG]

I was experimenting to see if it affects the mileage, and it does. Even my stock slant 6 is getting 3-4 mpg better on premium than regular, which does sound like a lot but the extra cost more or less balances out the gain. The best thing to buy is ethanol free gas, regardless of octane, which doesn't corrode the fuel system and you automatically get better mileage because ethanol burns richer than gas.

When I did the same thing with an 88 Ranger V6 it was only about 1.5 more, but premium was only an extra dime per gallon 30 years ago.

 

[PursuitSpecial]

I'm having more problems. This time I went on a trip and the car ran out of gas, I thought I had plenty, I filled the tank up a few weeks ago and had only driven the car about 100 miles, and about 60 miles into the trip it died, had to catch a ride to fill up a can. The gauge is stuck on 1/4 tank so I have to rely on mileage and knowing the tank is full to tell when I'm low. I'm beginning to suspect maybe the tank isn't venting properly so I'm getting a false reading if the tank spits gas out and turns the pump off, which will not fill the tank completely and throw off my mileage. The filler neck doesn't have a vent on the 1980 model and the only way the tank is vented is through the charcoal canister. Even if that's the case, I'm still not sure if that would cause the mileage to look so poor on paper, I got the same 9mpg figure this time after the car has been getting over 20. I guess I need to blow through the vent line to see if it's clogged and put up cameras around the car, unless someone at my work has been siphoning it in the parking lot.

 

[AJ/FormS]

I don't want to be the one but;
I have run the the compression ratio up on my combo to as much as 11.3, with cranking pressure approaching 200 psi, and ran it for 16 years on 87E10.
One combo I had went 32 mpg in overdrive with gearing that was making 65=1600 rpm.
So
the point is this, if your low-compression carbureted engine gets better fuel economy with better gas, then the tune is off in the first place.
BTW, IMO, there is NOTHING wrong with 10% Alcoholized fuel. I've been running it in my combo since 1999, same fuel system/same fuel pump/ same carburetor/same tank. and
whereas you said your car runs richer with alcoholized fuel, that is Not correct. Your engine needs MORE alcohol to run stoichiometric than gas. So when you add alcohol to gas, making no other changes, the mixture actually goes a hair leaner. However, at 10%, this poses no real problems.

 

[PursuitSpecial]

The problems are getting worse, my mileage is dropping to as low as 7 mpg now. I've noticed a trend though. Every time I fill up, I seem to be missing 2.5 to 3 gallons of gas, since if it took that much less to fill it up, the mileage would be around what it usually is. The shorter distance I drive between fillups, the worse the mileage appears to be, but enough time has to elapse between them or the loss isn't prominent. Road trips and cruising around town for a few hours makes it get good mileage but driving 5 miles to work every day for a week or two makes it go to shit. I thought it might be the tank slowly draining to the charcoal canister but I checked and it's dry. I thought it might be this new crappy high vapor pressure gas evaporating off, but that wouldn't account for the consistent loss in quantity, though if I leave the car sitting for more than about 3 or 4 days the fuel bowl is empty, same story with my gran fury. The only two things I can think of that will cause this is either a very slow leak around the filler neck or somewhere along the vent line, or a crackhead in my neighborhood stealing a 3 gallon can of gas once a week. I set up a marker on the gas cap so if anyone opens it I can tell.

 

[Remow2112]

Do you have a catalytic converter? If so remove it or hollow out and see if MPG improves. Go find a know 1 mile run. Mark odo and drive the 1 mile. See if odo is close. Is the choke opening all the way? What is the idle timing setting? Do you still have the vapor return system on the fuel setup? Make sure it is not leaking. Is the tranny slipping?

 

[PursuitSpecial]

I took the catalytic converter off when the muffler fell off, I checked my odometer against Google maps gps on a 119 mile trip and it measured 124 miles so it's not terribly far off with my slightly shorter tires. I just replaced the choke pulloff a few months ago and it comes off fine. I haven't checked the timing, but I doubt it would cause what I'm seeing. The vapor return is still hooked up but I've checked it for leaks, no liquid fuel there, just strong vapors. The transmission has been replaced with a non lockup converter unit which does hurt the highway mileage a bit, it doesn't feel like it's slipping, the converter is very tight and it has no trouble accelerating and maintaining speed with light throttle pressure, but I plan to replace it with a wide ratio lockup 904 if I can find one to help the takeoff power and highway manners. And btw, out of curiosity I stopped at the station again today and filled up, it only held 0.43 gallons to go 7 miles so the leak isn't occuring all at once when I fill the tank.

 

[Justwondering]

Pursuit --
Maybe a camera is called for.
A person I know might have been frustrated with a teacher in high school and just might have been in the parking lot when said teacher was on the football field during practices.
Said person spent two weeks siphoning gas from teacher's car and listening to him complain in class (cause we all knew he couldn't do basic math in the Algebra class he was teaching).
Then, perhaps this person spent another two weeks topping off his tank every day. And listening to his confusion about his magic car.
Then one afternoon, seems like all the gas 'magically' disappeared out of his car. What a whiner he was the next day.
Ahhh , just saying, it could be a motivated, beyond-your-view 'problem'.

JW

 

[Justwondering]

And no, I was not the person that put the banana in his tailpipe.
As stated in another thread, my choice was always stinkbait under the driver's side exterior handle.

JW