Poor gas mileage

Unknown

To be six cylinder vehicles, neither the Hudson nor the Kaiser are very fuel efficient. I'm going broke just trying to joyride on the weekends. Are these cars known to be gas hogs? Would switching to electronic ignition make a big enough difference to justify the cost?

Jason

Jon B

Depends upon your definition of 'gas hogs.' What kind of gas mileage are you getting (and have you checked your odometer against the green mile markers on the nearest Interstate, just to be sure you're accurate)?



I'd say for cars of that era, 21 mpg would be exceptional for all-around driving, 17-18 mpg would be 'good'. If you're looking for substantially better than that, you might want to look into a vintage Rambler!

[Deleted User]

Switching to an electronic ignition will get you a hotter spark but will not improve your gas mileage significantly. The cause of bad gas mileage could be as simple as needing a new set of plugs up to needing a good tuneup. I pulled down the Carter carb on mine gave it a complete rebuild threw in a new set of plugs properly gapped and made sure the timing was spot on. I am getting better than 20 mpg on the highway. All depends on how you tune them. It also helps that I have a 60's Snap-On Engine Analyser and I am a bit of nut for having all my settings dead on.



On gas mileage I have a video of Marshall Teague at Daytona beach he did the complete 150 mile race on a single tank of gas. I know he had the bigger tank but on the back straightway he averaged 88 miles an hour. Pretty darn good for a 51 Hornet.

Unknown

Jason, like Jon said, it depends on what you mean by "gas hog". Some other things to check would be, vacuum leaks,valve clearances, and do a compression check and leakdown test. You may find that your motor is not bad enough to need a rebuild, but just a little out of spec!

Club Coupe

Along with a good, major tune up; check all gas lines to make sure that you don't have a leak. This new unleaded gas seems to eat the old style gas lines. Over the last two years I have had to replace every gas line on all of my older vehicles due to leaks mainly in bends where gas can collect when the car is not running. A lot of the time the leak could not be detected until the car was running. Changing the gas filters isn't a bad idea either.

Park_W

Also check the vacuum advance diaphragm ... a bad one will have quite an effect on cruise fuel consumption. Disconnect the vacuum line, take the advance arm loose from the breaker plate, then push the arm inward against the spring pressure, put your finger over the vacuum line hole, and release the arm. If the diaphragm is good, the arm will come out a little, but not all the way ... it should pop out further when you take your finger off the vacuum hole. If the arm pops all the way out immediately when you release it, the diaphragm is bad ... get a new unit.

brnhornet52*

Hi Jason,

Hudsons, especially in the postwar era were not known for fuel economy. In fact many of the road tests of the new cars used figures of 13 mpg city and 16 mpg road.

But with gas at 0.19 a gal, who cared? One interesting point in Harry Krauss's book is that hudsons were engineered to run well on the cheapest, lowest octane available at the time. The logic was that if it would run good on this type of fuel, it would run well on whatever the owner would purchase.

With both careful tuning and careful driving, you can achieve surprising results. My well worn Hornet will consistantly obtain 15.7 mpg city and 19.7 mpg road with the 2bbl carb and speeds up to 55 mph. Expect about 3 mpg less with the TwinH.

Unknown

Actually, I'm not too concerned with the mileage in the Hudson. It's not too bad. But the Kaiser sucks up half a tank after a little over 50 miles. It has the supercharger, but I don't even use it except to show off once in a while. I changed the plugs two days ago and there was a lot of carbon on them. The vacuum advance is new, so I don't think that's the problem. I checked the gas lines and didn't see a leak. Any more ideas?

Jason

hudsontech

Unfortunately, vintage Ramblers weren't all that great either. The 6 cyl's from the 1960's era got 19-21, surprisingly the V-8's got (overall) 20-22.

A lot depends on your driving habits - if you want to roar out of a stop light, mileage will, of course, be less. If you drive conservatively you'll get around, as is said, 17-19, maybe 20 mpg. In an era when gas prices were below 35 cents a gallon, who worried about milage.



Hudsonly,

Alex B

Club Coupe

Jason, I would closely check the timing. You may not want to rely on a timing light 100% and time it manually during driving. Also, how large is your gas tank? If it is a 20 gallon tank your information has you getting 5 miles per gallon, which is poor by today's standards. However, as Hudsontech said when your car was built, gas prices were low and nobody really cared about mpg. I have a 1972 Chevrolet with a 400 cu in "mouse" motor and get between 7 and 8 mpg around town. The standing joke is that the car will pass everything but a gas station. I also have a 1975 Pontiac with the standard 400 ci in motor and get between 10 and 12 mpg around town with it. So go figure?