Mustangmaster

I live in Charlottesville, Virginia and took a trip to Orlando, Florida last week. Here are the MPGs and speeds I drove to Florida then back to Virginia. I drove even further south to visit a nephew in West Palm Beach, Fl. We also visited someone in Alpharetta, Georgia on the way back. I kept my tire pressure at 32 PSI.

1st tank: 31.1 MPG, 93 octane ethanol free gas w/91 octane Brenspeed tune, 58-63 MPH

2nd tank: 27.2 MPG, 93 octane E10 gas w/91 octane Brenspeed tune, 70-75 MPH

3rd tank: 29.1 MPG, 93 octane E10 gas w/91 octane Brenspeed tune, 65-70 MPH

4th tank: 26.2 MPG, 93 octane E10 gas w/91 octane Brenspeed tune, 70-75 MPH

5th tank: 26.4 MPG, 93 octane E10 gas w/91 octane Brenspeed tune, 70 MPH

6th tank: 30.9 MPG, 87 octane E10 (I think) gas w/87 octane Brenspeed tund, 60-65 MPH

I have the Ford Racing CAI. Speed has a lot to do with how good or bad gas mileage can be. A few days before this trip I went to visit my father who is 125 miles away from me. I visit him almost every week. This last trip I got my best MPGs ever....34 MPG on 93 octane ethanol free gas after filling up and driving directly to his home, then back and filling up as soon as I got back. I drove 50-52 MPH the whole way as it's a 55 MPH speed zone.

I do get a jump start on good gas mileage because of where I fill up at the ethanol free gas station. It's just over Afton mountain, 15 miles from my home. After I fill up I go up the mountain which is 3 miles up and a not too steep a slope but, when I go back down the other side, I put the car in neutral and drift for the 5 miles down the steeper slope side. By the time I get to the bottom, the electronic readout of MPGs says anywhere from 36-41 MPG. Of course, as I keep driving the MPGs slowly get lower. Either way, this is great gas mileage from a car that goes from 0-60 in 4.5 seconds.

Nuke

Excellent. Continue keeping track (better to hand calculate, though) and you'll begin to get a very good feel for what affects your car's average fuel mileage in the months to come. Most folks don't realize that you need quite a few data points to even begin to get close to what your car's average fuel mileage really looks like.

I've kept strict fuel mileage records on all of my vehicles over the past 1,500,000 miles and there are many, many variables. But 2 obvious ones that you've hit on are ethanol content and speed. Of the 36,000 miles currently on my "garage queen", about 34,000 miles are trips of 400 miles or more one way so I've had the ability to really nail down some of those variables.

Mustangmaster

All of the figures are hand figured except where I said coming down the mountain the electronic readout says...

Nuke

LOL! Toss out and forget any of the on board data other than the figures for pump-to-pump but it seems you already know that. I always want to smack folks when they punch the reset or have just pulled out of a gas station and are coasting down a long grade or simply resetting the onboard while at a steady cruise and state "my stang gets 40 MPG!".

baddog671

Good numbers. Mine seems to be best in the 55-60 mph range

Nuke

Although it's like scraping nails across a blackboard, try a steady cruise after a fill-up at 50-55 MPH (about 1500RPM). I typically get 27-28 MPG, hand calculated on my GT, pump-to-pump. There's a road called the Natchez Trace Parkway that runs from Natchez, MS to Nashville, TB and it's a 50 MPH speedlimit, 2 lanes. Gorgeous trip but, dang, it'll drive you nutz...

Norm Peterson

That is a really. bad. idea.

It is not worth the few fluid ounces of gas to give up engine compression braking or the immediate availability of acceleration. You won't always have the luxury of the extra time it takes to get it into gear without disturbing tire grip.

In some areas (if not most), it is specifically illegal to let the car coast in neutral.

A little leading throttle (emphasis on the word "little" here) tends to make the car more stable while you're cornering. You can't do that when you're in neutral; you're riding in a glorified downhill soapbox racer at that point.


Mid 20's @ 70 - 75 or so with the FRPP cold air & tune is entirely believable.


Norm

baddog671

Yes, going 55-60mph, 5th gear, around 1500-1600rpms seems best. After leaving a fillup I can average some nice numbers for the next day or so, but it'll slowly dwindle down. Mountains are a killer, and I don't always drive slowly.

I usually average 21-22mpg with the vast majority of my trips under 15 miles.

baddog671

I coast mine in neutral all the time aswell, Norm

Mustangmaster

If I remember right, coasting in neutral vs leaving in gear going down hills has been discussed here before. I think most people decided it was better to go neutral because brakes cost less to replace than transmissions. Don't remember the legality of it. How would a cop know you are in neutral?