lol that shows 1gal an hour at idle, thats a bit of a difference right there.... a 4 cylinder would most likely stall and be flooded at 1 gallon / 5minutes at idle speeds, and that email was based on vehicles with more cylinders and far worse mpg for the big rig and a 20mpg vehicle,
but yeah, the idle will throw off the mpg the longer you idle cause it does take fuel to keep the car running, the would be reasonable to assume, but your car running through 17 gallons in an hour and 25 minutes when you can drive at 80mph for 6ish hours

 

Alright, well it looks like Im gonna head in town soon...ill fill up and see my mpg then most likely im gonna buy a metal gasket and more high temp ret rtv silicone and get to work.Ugh....so it begins.

 

Okey Dokey! Well, I had 85 miles on the trip meter since I filled up after going in town and then could only put 2.4 gallons in...so thats about 35 mpg. What the heck? I drove 30 miles on the interstate of the 85 and the rest was 55 and 30 mph stop and go traffic...so I am lost.

No one has my gasket in stock, so Im gonna see the mpg again and see what she gets me.

What should I get @ 70 mph on the interstate w/ and w/o ac?

 

Well I avg 32mpg on I-5 with and A/C on going 70-80.

 

I've pulled off 32-35 on the interstate at 70-80 over a 240 mile trip (including the two mountain passes), so I'd say 30-32 is pretty good.

That's W/out A/C windows up...

 

So why do you think I first got 26 mpg, and when I just put ina couple galons to fill up, it was so high?

I am lost :-(

 

i think youre really assuming youve used 2.4 gallons, the only way to truely know is to only have, say 3 or 4 gallons in the tank then drive topping off isnt extremely accuate after all. All i know is i havent been getting good gas mileage for a while now, dont know what to link it to cause between the larger throttle body, 255lph fuel pump and possible bend valves its kinda hard to narrow ^_- but before that i was getting 35mpg highway and 26 city, now its 23 city and 28ish highway

 

I too have always wondered about how accurate topping off really is. I mean, how do you know the gas pump cuts off at the same exact pointevery timeyou fill up? You don't

 

Well, everytime I fill up there is a little gas I can see...so I would assume that it fills up the same everytime since I see that everytime I completely fill up.

 

The easiest way to get consistent numbers is to use the same pump at the same gas station each time. Try to rule out as many variables as possible since some pumps cut off differently than others.