Mileage poll 65 C-30 283/SM420/4.10's

[66Submarine]

Alright, got my first results in, what's your guess?

Specs: SRW C-30 pickup, 2 barrel 195HP 283, SM420, 4.10 gears, and some old 7.50-17 bias tires. Drove kinda hard and ran about 50MPH in rural areas and ran 60-65MPH on the highway. Didn't got WOT every shift but I kept up with late model cars for the most part, wasn't easy on it. Also had some idling at lights, lugging on hilly backroads, and the carb leaked or something and it idled down a bit once.

[hotroddr]

Im guessing 12 mpg

[LT1 Burb]

7.5 mpg
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[MikeS.]

8.0
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[scottofksu]

6 mpg!

[ACK]

3 gallons to the mile!!!

[Corts60]

I'm going with 8 mpg on a good day.
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[Rich 5150 69]

6 mpg...!

[rideblue00]

10. Is the choke working properly?

[66Submarine]

And the answer is... 13.3MPG. 32 miles on 14.5 pounds of fuel. Not bad for a tired old one ton, IMO! Driving more normally (for me), I think I'm probably getting something like 15MPG now (I'm going to run a few more miles and check it). The choke works perfectly... for max economy anyway; wired all the way open all the time.

It's my daily driver now, btw, and so far it's been great. With the 4.10's and the tall tires it will run with traffic just fine if I want/need to, will pull/haul most anything I have reason to, and the mileage is even decent. And to think if I wouldn't have bought it, it would almost certainly be Chinese silverware by now...

[brokenspoke]

Your speedometer is off.....how much is 14.5 pounds of fuel?

[66Submarine]

The distances came from Google Maps, not a 48 year old blown up speedo; 14.5lbs / 6lbs per gallon = 2.41 gallons. 32 miles / 2.4 gallons = 13.3. I parked in the same spot and measured/filled with a dipstick to within 1/16" or better. An inch was about one gallon so within a half pint or so. The dipstick is a piece of copper tubing that I slide in touching the top and bottom of the filler neck so it hits the same spot in the tank. I measure the fuel level when I start, count the miles, and fill it up with a 5 gallon can to the original level. I weigh the can before filling, the full weight minus the weight after filling = fuel used in pounds / 6 pounds per gallon = gallons used. The weight of a gallon varies slightly by temp and is actually normally more than six pounds IRL.

I don't know, I've just never managed to get the mystical 10-12 MPG myself in anything that ran good. My worn out 250 powered '65 C-10 got 18MPG @ 50-55MPH. (This taken over 80 miles distance and verified several times.) I don't have anything with a TH350 or TH400, maybe that's some of it? I really don't know. If the truck really got 8MPG I would have burned 4 gallons in my 32 mile trip. That's 24 pounds @ 6lbs/gal. I could say a couple pounds or something, but nine and a half more?!? No way.

Now it's time for me to take my pills.

[Rich 5150 69]

Originally Posted by 66Submarine

The distances came from Google Maps, not a 48 year old blown up speedo; 14.5lbs / 6lbs per gallon = 2.41 gallons. 32 miles / 2.4 gallons = 13.3. I parked in the same spot and measured/filled with a dipstick to within 1/16" or better. An inch was about one gallon so within a half pint or so. The dipstick is a piece of copper tubing that I slide in touching the top and bottom of the filler neck so it hits the same spot in the tank. I measure the fuel level when I start, count the miles, and fill it up with a 5 gallon can to the original level. I weigh the can before filling, the full weight minus the weight after filling = fuel used in pounds / 6 pounds per gallon = gallons used. The weight of a gallon varies slightly by temp and is actually normally more than six pounds IRL.

I don't know, I've just never managed to get the mystical 10-12 MPG myself in anything that ran good. My worn out 250 powered '65 C-10 got 18MPG @ 50-55MPH. (This taken over 80 miles distance and verified several times.) I don't have anything with a TH350 or TH400, maybe that's some of it? I really don't know. If the truck really got 8MPG I would have burned 4 gallons in my 32 mile trip. That's 24 pounds @ 6lbs/gal. I could say a couple pounds or something, but nine and a half more?!? No way.

Now it's time for me to take my pills.

I believe gas weighs in at 8.34 lbs per gallon, you`ll need to revise your fiquires....

[66Submarine]

Actually, 8.34 is for water. Gasoline varies by blend and temp, but is generally 6.1-6.3 or so from what I've read. Six is just an easy number, that in this case also provides a little margin for measuring inaccuracies. (Using 6.2lbs/gallon I come up with 13.7MPG.)

LVPhotos: Is it FU button as in "FU other drivers", or "FU T-5"?

The late model thing has me puzzled a bit, too. I don't really see why I can get very close to late model mileage in a 48 year old truck with no mods, but apparently I do. I guess the lighter weight, lack of brake drag (all wheel drums), lack of accessory load, etc. all adds up.

And so far, it looks like I'm actually going to get a better number this time; something like the 14-15 I figured I would get. I'll report back in a few days when I've got the results.

[LT1 Burb]

I don't buy it, my 3/4 ton fuel injected silverado only gets 13 with 4:10's and a 4 speed auto. BTW fuel is 7.5 to 8#'s a gallon so that means you would be getting 16 MPG or more.

[ChrisDollins]

13.3 is pretty awesome! That's all my brand new 2500 ext cab, 4x4 with a 6ltr and 6 speed auto and 3.73's would get.

Chris
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[LVPhotos]

Well I get close to 20 if I layoff the Fu button. 406 small block 400hp/475flb, t5 overdrive .67, 3.73 posi 28" tire.
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[gofastnut]

Good deal!! Just please, PLEASE don't "hypermile" in that old truck, that would be shamefull!

[LVPhotos]

That would be for the drivers here not letting you in or on road with signals. The lane drifters and slow drivers in the fastlane. Yes its old and primered but its all new under that Hood. I like to take it easy for the most part but let them ponies run now and then. The t5 does it job considering it getting 475 flb, 200 more than rated for.
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[joedoh]

I've seen all kinds of fancy ways of measuring mpg and this one is brand new to me. 13mpg just seems, high. I dont know if you got 13mpg or not, but I know when I hear hoofbeats I think horse and not zebra.

[66Submarine]

Wow, I never would have thought 13MPG would be an unbelievable number. I actually am shooting for more like 15MPG, ha ha. Guess that's why I like three pedals and an inline six or small sb.

I think this method is pretty accurate. Normally, I know people fill to the cutoff at the same pump and use the odometer, but personally, I think that's relying on a lot of variables. Plus I don't own a truck with a functional speedo/odo anyway. For me I like this method. Easy to do, no speedo inaccuracies, no relying on the pump auto shutoff, etc.

Sounds a lot like driving in Atlanta, LV. At least in the outskirts there's less of "them". I still can't believe how many new cars come without any turn signals... Another favorite of mine are the nearly-new cars with one headlight, one brake/signal light, etc. Guess that extra bulb was optional or somethin'.

[hopped up]

I woulda guessed about 5mpg. I get 12mpg with 350/350 and 3.73 rear gear
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