[carbking]

I went down a different path with gearing. Since my 360 will turn enough RPM's for a wide torque/HP curve; I left the stock rear gear (1974 4-speed), but changed to an ultra-wide ratio 4-speed.

Jon.

[Half-Inch Stud]

Originally Posted by carbking

And weight! Jon.

well okay if you be driving uphill most of the time.

[77 TRASHCAN]

Jon, you need to post a picture of your some day...

[HWYSTR455]

Best mileage I had with the LeMans, 461, 4L80E, 373s, 26" tire was measured on a 60mph average, rolling hills, about 500ft elevation was 23 MPG. That was done going to, and from a destination, both numbers were the same.

Like others, my issue with collecting MPG data was due to the right-foot variable.

.

[David Jones]

Right after I put the TKO in, I got curious about mpg's. I posted this in a thread.....


"This morning I woke at my usual 5:30 and decided I'd take the GTO on a freeway run. I rolled into the Chevron at 6 and filled up --124.3 miles on the odo. I drove down to the Jack's drive through and got a sausage/egg biscuit for the trip. Back up past the Chevron I rolled up to 5000 rpm for a couple of friends outside the station sipping coffee. So much for fuel economy. About 3 miles to the freeway and off to Tuscaloosa, about 40 miles away. I run "about" 75 most of the way up and back. I saw 90 once. At 75 the tach is running about 2100+- rpm. The new OD is nice. At a steady freeway speed, windows up you can tell these 8 year old Radial T/A's are similar to Fred Flintstone's tires. Fairly hard and square. The drive train is smooth though and the trip is good. I roll back in to the same pump at Chevron and put in 5.064 gallons. I have been exactly 90 miles. --214.3 on the odometer. 17.77 mpg. 19mpg if I'd have tried? She did 13.20 @ 105.5 with a 2.10 60ft last time I went to the strip."

[carbking]

Originally Posted by 77 TRASHCAN

Jon, you need to post a picture of your some day...

As requested:



Note that everything is green!

Jon

[David Jones]

Green is good.

[TCSGTO]

It seems like most who check gas mileage on an old car make an effort to have optimum conditions and drive with economy in mind. I get that but I encourage more to drive the car like you normally would without mileage in mind. Burn some tire, let it idle, open it up a little, drive through city traffic, turn on your AC if you have it, etc. THEN check MPG's. To me that's the true MPG a car gets when it's used as intended.

Kind of like the EPA ratings where car companies tune and equip a car to get max mileage on the test loop then no one can duplicate it when they actually drive the thing everyday.

[i82much]

I seem to recall getting 14 or so driving an easy 50 mph on country back roads with my 505, 850 double pumper, wide ratio muncie and 3.54 gears with 28 inch tires. 65 GTO, about 3650 lbs full of gas without me in it.

Good enough for a weekend car, and not much different than my 6.0 2500HD daily driver.

[Cliff R]

Jon, nice John Deere tractors next to the GTO!

I just finished a JD 730 and just about done with a model 60. The belong to my brother and I'm doing the engines, transmissions and 12v SI alternator conversions. Also converted the 730 from "pony" motor start to electric......Cliff

[Formulajones]

Originally Posted by TCSGTO

It seems like most who check gas mileage on an old car make an effort to have optimum conditions and drive with economy in mind. I get that but I encourage more to drive the car like you normally would without mileage in mind. Burn some tire, let it idle, open it up a little, drive through city traffic, turn on your AC if you have it, etc. THEN check MPG's. To me that's the true MPG a car gets when it's used as intended.

Kind of like the EPA ratings where car companies tune and equip a car to get max mileage on the test loop then no one can duplicate it when they actually drive the thing everyday.

We probably have some of the worst conditions for gas mileage around here. Mountain terrain where you're constantly going up and down long grades and sometimes very steep mountain sides. Factor in the elevation of 5,000 feet around the house that changes drastically in any direction. Couple that with our 100+ degree temps in the summer and our density altitude easily climbs over 8500 feet during the day. Makes for a tuning nightmare. Not to mention the million plus people that live in this little town, you almost can't avoid traffic.

All the figures I posted above are driving in these conditions. If I were driving on flat ground and low elevation I wouldn't be surprised if those numbers picked up a bit.

Our daily drivers I fill up weekly, I constantly check the mileage as just part of the deal. Force of habit and it tells me something is wrong if the numbers are way off. The Z consistently gets 15 mpg every week in around town traffic, stop and go, on 35-45 mph streets. My 70 Formula consistently gets around 14 mpg in those same conditions. Both cars jump to 17 mpg on the highway, before the Z had the overdrive.

[ta man]

Originally Posted by TCSGTO

It seems like most who check gas mileage on an old car make an effort to have optimum conditions and drive with economy in mind. I get that but I encourage more to drive the car like you normally would without mileage in mind. Burn some tire, let it idle, open it up a little, drive through city traffic, turn on your AC if you have it, etc. THEN check MPG's. To me that's the true MPG a car gets when it's used as intended.

Kind of like the EPA ratings where car companies tune and equip a car to get max mileage on the test loop then no one can duplicate it when they actually drive the thing everyday.

I know mine eats a lot of fuel full throttle. Since my tank isn't sumped, I normally go to the track with 3/4 of a tank of fuel. In 5 or 6 passes it will be at half.
So the way I love driving it...15/16mpg cruising or less than 1 mpg at the dragstrip.

[77 TRASHCAN]

Thanks Jon!
I've heard you talk about it, here and there.
I've never seen a green one, anyone else?
The Pontiac Oakland event is in Tulsa next year (Early July) maybe you could drive it on down?
Thanks again!!!

[68WarDog]

Is that correct, #76 primary jets, 517 cubic inches ?

[i82much]

Originally Posted by 68WarDog

Is that correct, #76 primary jets, 517 cubic inches ?

My 505 has an RPM intake and an 850 double pumper. Still rich with 76 jets in the front. I think big street engines give a lot of signal and need small jets up front with a big PVCR.

[carbking]

Originally Posted by 77 TRASHCAN

Thanks Jon!
I've heard you talk about it, here and there.
I've never seen a green one, anyone else?
The Pontiac Oakland event is in Tulsa next year (Early July) maybe you could drive it on down?
Thanks again!!!

The BSG color is original; it does kind of go with the Deeres.

As far as your other question; the car will not see another POCI event in my lifetime. No other comment on the subject.

Jon.