Technical Fuel mileage

I challenge anyone getting that poor mileage to let me put an O2 sensor in a collector or downpipe, and let me show them.

In all of my tuning time using a wideband Oxygen sensor, I have NEVER had a vehicle come in, no matter how good it ran, or how fast it was, that was tuned properly, by "feel".

My best to-date has been a 3.11x increase in freeway fuel mileage.

That car ran great when it came in. According to the customer, anyway.

Hot rods are supposed to foul plugs, right?

I never did check the before and after mileage of the mild SBC 350 who's owner put on a 1050 Dominator.

 

Oh, I get decent mileage out of mild 350s. It's the quick cars that don't do so well. And yeah, I've had a wideband on the carbs (on a different motor), pulls about 13 afr cruising.

 

Does this look fouled? been in there about a year, I think....that's well over 2k miles.

 

With my 1938 Plymouth pick-up I get over 19 mpg on the hiway all the time, occasionally over 20 mpg when the wind is right. 360 4 barrel, 5-speed manual x-15, 3.23 rear gear.

 

306 SBF Alum Heads 2 600 Holleys
16 @ 70 mph
zip in town

 

Just a Hobbyist, but putting 900 or 1000 CFM on 3 or 400 H.P. motor will kill any kind of Fuel mileage. Over Carburation is the no. 1 killer of Power Torque and Fuel Effiency.

 

I dunno My 66 GMC with 250 six and 336 rear gears don't seem to guzzle gas. My OT 86 chev 3/4 ton with 350 2 bbl likes fuel. Put a load on it or behind it and it really guzzles the gas. Ive never owned a 350 that didn't guzzle gas. I wish the 86 truck had a 305 V8 or a 250 six. However its not any problem for me to afford gas at present. When I was younger sometimes I couldn't afford to fill the tank.

 

Ive owned a few of those V6 GMC engines and they got a wopping 4 MPG and didn't puff any black smoke or foul sparkplugs. They would pull any load you wanted hardly ever has to downshift on the grades. anywhere from 305 cu in to 478 cu in 4 MPG was the best I ever got.

 

Now I really don't care about the mileage so much. I have taken steps to improve it somewhat but I'ts a Hot Rod so I really don't care. He asked so I responded.

 

If I had a real hotrod gas mileage would not be the top priority but since I do drive a couple long distances I do have to think about it since I do not have a money tree in my back yard.

 

My wife and I planted a money tree many years ago, it's nice to have....especially when you drive something that gets 7 mpg

 

I need to know where you get them since they can not be found up my way.

 

Gotta plant them when you're young.

 

Too late now.

 

Last week, 1300 miles, 21.8 total mpg. I've also discovered my odometer is registering 7.5 miles for every 10 miles traveled, according to those little markers on the Interstate.

I should probably recheck my numbers, mileage is probably better then I thought.

Its probably a wonder I haven't gotten any tickets for speeding yet...

I should get that corrected, how does a guy get a speedo corrected?

Oh yea, 3.9 EFI V6 Dodge with an OD 5 speed and 3:55 rear gears. I thought I was getting 17-18 around town... Gene

 

Note to self. Get fountain of youth, then money tree.....

 

usually you change the driven gear in the transmission.

 

This 5 speed has both a speedo cable and an electronic sensor, (the next year they did away with the cable), does it still have a changeable gear?

 

If it has a cable, then it has a gear. I don't know what they look like inside, but I bet you could take it apart and find out!

 

I think that one actually does. If memory serves me, until the end of the production run, you can pull out the electronic drive, which has a drive/driven ge****t, and put in a cable one, or, in your case, just put in a different driven gear.

I think these cross reference with Jeep speedometer gears.

 

My time machine will be finished a few years ago.

 

15.681 US mpg on the highway,,i should make a point of improving on this immediately

 

Very pleased with my 59 Edsel 223 - 2 speed auto 18-20 mpg local driving 10 mile radius and 24-25 on motorway at 70 mph (UK gall = 4.55 liters to gallon )

 

I thought you guyf across the pond used hogsheadf to the furlong.

 

Dodge speedometer driven gears are about 3% per tooth so you would need to replace it with a driven gear with 8 teeth less than the one you have now. That should correct most of the error. Don't forget to line up the speedometer sleeve with the amount of teeth of the driven gear, you might have to rotate the sleeve.

 

Truck64 that was the old system, the new one is called ROG rip off government , basically works out as
1 USD per gallon = 3 UKP per gallon LOL

 

Oh, man. That milage ****s => How many pounds are you hauling at that point? I had no idea trucks got that low of mileage. I thought the diesel would help you.

 

The average gross weight with this particular load is usually between 75000 and 80000 pounds. The load itself is around 45000-50000 on average. Big diesels make a ALOT of power and the cost of power is fuel. This engine makes 500hp and 1850lb ft if torque. If you're getting 6-7 mpg in a rig pulling a load you are doing good. Some may do slightly better with a tune.

 

I would have to drive the Ford like a normal person to see any big difference. So far I've tracked my MPG twice and got 10 and 9.4.

 

The Pete is efficient today. Gross wgt 77000.



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