good read.... clocked my MPG'S

[jake wells]

Well i did a experiment with my trucks both have 20 gallon tanks V8's and manual transmissions 3spd and 4spd.
the 64 had a 4:11 posi and the 78 had a limited slip 3.07.

I drove the 64 with the timing set spot on and the carburetor leaned a little. From empty to full i clocked 10.1 mpg city 13.8 highway not to bad for no emissions.

My 78 the timing was set to factory settings and my carb was leaned a tad .
( Had to take the little factory plugs out to adjust them. )

I drove it from empty to full and averaged 12 highway 15.7 city. that's pretty good considering it has a 2 barrel and no overdrive .

 

[Irishman999]

I like this thread, I could really get into this. I have been trying to monitor my MPG's since I got the 85 running but dont feel like running out of gas in traffic.

My plan was to basically fill my gas can with exactly 5 gallons, run it completely out and put the can in it. Drive it around in the city until I run out again so I know exactly what I am getting.

If I could get a baseline MPG i could start experimenting.

 

[CknightK10]

89sub would love this tread!

 

[davbell22602]

Nice

 

[89Suburban]

@jake

I am a little lost on your post. Did you run the whole tank for each test? And did you run separate full tanks for the city vs. highway? Just trying to understand how you got the separate city/highway numbers.

Those are fairly good mileages you got.

 

[jake wells]

@Jake

I am a little lost on your post. Did you run the whole tank for each test? And did you run separate full tanks for the city vs. highway? Just trying to understand how you got the separate city/highway numbers.

Those are fairly good mileages you got.

yes i ran separate tanks but i used off road gas with it
100LL it means 100 octane low lead Av gas.

reason being it does help the 78 some but it insures my heads on my 64 since it doesn't have hardened valve seats
it has no ethanol either and has a nice smell when i burn it kind of like something sweet.

 

[jake wells]

I like this thread, I could really get into this. I have been trying to monitor my MPG's since I got the 85 running but dont feel like running out of gas in traffic.

My plan was to basically fill my gas can with exactly 5 gallons, run it completely out and put the can in it. Drive it around in the city until I run out again so I know exactly what I am getting.

If I could get a baseline MPG i could start experimenting.

just make sure you get it running really good first. you don't want to back up traffic with a stalled truck

 

[Irishman999]

just make sure you get it running really good first. you don't want to back up traffic with a stalled truck

I dont have a problem holding up traffic, I ran out in a mcdonalds drive through last summer. That was a pain in the ass. Seriously right after I stopped at the first window to pay I just started to take off and that was it.


(My gas guage is broken, my right side tank has holes in it)

 

[89Suburban]

yes i ran separate tanks but i used off road gas with it
100LL it means 100 octane low lead Av gas.

reason being it does help the 78 some but it insures my heads on my 64 since it doesn't have hardened valve seats
it has no ethanol either and has a nice smell when i burn it kind of like something sweet.

That must be a KY thing. Up here in the **** hole NE, we got, 87, 89, and 91 octane, unless ya hit Sunoco for 94. I just stick with the cheapest, low life assed local station with the water downed **** for 8 cents less a gallon than everybody else.

 

[89Suburban]

That must be a KY thing. Up here in the **** hole..

(Hey old77, here's a quote for yer qoute thread for tomarrow mornin'. )

 

[HotRodPC]

I like this thread, I could really get into this. I have been trying to monitor my MPG's since I got the 85 running but dont feel like running out of gas in traffic.

My plan was to basically fill my gas can with exactly 5 gallons, run it completely out and put the can in it. Drive it around in the city until I run out again so I know exactly what I am getting.

If I could get a baseline MPG i could start experimenting.

DOH !!! Oh hellllllllllll no. That's not how to you figure mpg.

Fill your tank till the pump knocks off the filling and round it to the next .25 cents and go pay for your gas. Write down your odometer reading with the full tank. Drive the truck as you normally would to about 1/4 tank, or even 1/2 tank. Then fill it back up to where the pump knocks off again. Write down the gallons to refill the tank to knock off point. Now get the odometer reading again. Subtract the last odometer reading at fill up from the odo reading with the new filled tank. Lets say its 200 miles. And you put in 15 gallons to refill the tank. Divide the 15 gallons into the 200 miles and that is your MPG. Its the most accurate way to do it. I just assumed everyone knew that.

 

[HotRodPC]

yes i ran separate tanks but i used off road gas with it
100LL it means 100 octane low lead Av gas.

reason being it does help the 78 some but it insures my heads on my 64 since it doesn't have hardened valve seats
it has no ethanol either and has a nice smell when i burn it kind of like something sweet.

Yes, and do be careful running that AV gas. For those who don't know. Av gas is aka Aviation Fuel. Aviation fuel in some blends can be very very lean and cause excessive combustion chamber heat in your motor and you can actually melt your rings or pistons, rapidly burn valves or as mentioned with no lead damage non hardened seats. Way long time ago, we used some av gas in race cars. But was also added a teaspoon of SAE 30 motor oil per gallon just for some lube properties. It ran well and was like 103-105 octane back then. In the days when you could run a 12.5:1 compression.

 

[jake wells]

Yes, and do be careful running that AV gas. For those who don't know. Av gas is aka Aviation Fuel. Aviation fuel in some blends can be very very lean and cause excessive combustion chamber heat in your motor and you can actually melt your rings or pistons, rapidly burn valves or as mentioned with no lead damage non hardened seats. Way long time ago, we used some av gas in race cars. But was also added a teaspoon of SAE 30 motor oil per gallon just for some lube properties. It ran well and was like 103-105 octane back then. In the days when you could run a 12.5:1 compression.

i put marvel mystery oil in my gas for lubricity and to keep my fuel system clean but also i have to run that stuff in my trucks or it pings and rattles it corrects that problem i tried 93 and it doesn't help.

 

[HotRodPC]

You are running either to far advanced timing, or very high compression.