Curios on MPG and Fuel Tank Range With Various Engines

[F500guy]

So I took a 225 mile trip yesterday from Portland to the beach, up the coast and back. I was able to get about 13.5 MPG with the 427 so looks like I could get 200 miles a tank (no activating the secondary :() Out west here it is pretty easy to get 50+ miles or more between gas stations on the rural routes. On long trips cross country, looks like I better know where my gas is going to land me. Interested in the other approach for folks that take long trips.

[PNWTim]

Sounds like a great road trip and the weather yesterday was about as good as it gets for this time of year. I have a Coyote in my coupe so I am thinking I may get more like 20 mpg which alleviates those concerns somewhat. I have used one of the fueling apps in the past which work pretty darn well. You can apply filters i.e. drive no more than 150 miles, etc. to ensure you don't pass the "last gas for 52 miles" sign with 2 gallons left in your tank.

[Jeff Kleiner]

My old car, a Mk3 with a moderately built 302 and Ford EEC-IV EFI, T-5 and 3.55 rear would pull down 22+ MPG running a steady 75-80 on the interstate. My butt would get tired long before a full tank ran out!

Jeff

[J R Jones]

Garmin offers a range of Navigation devices, I have an RV 780 with way more than fuel availability, like (approaching) speed limits and the next intersecting road name.
My Tesla blows the Garmin away with navigation information. Besides all of the above, I get Supercharging data like my range arriving, how long a charge will take, cost, and how many spots are occupied.
My roadster gets ~15MPG from a 302 with a 3.55 RAR daily driving.
jim

[Steve1979]

I have a MK3 with a SMB Ford ~310+hp (carb), T5z, 3.27 gears and stock Mustang gas tank (15.4 gal?). On an 800 mile trip some years ago, I was getting approximately 23.x mpg on some parts of the hwy. This highway is the 101 from San Jose to Huntington Beach, lots of different driving conditions. With the 3.27 and overdrive it reminded me of driving a boat, because you are cruising at such a low RPM on the hwy, like below 2200 on some stretches of the road.
Because we didn’t know where gas stations were located, we made it a point to stop and put gas in whenever we hit ~ ¼ of a tank. With your gas mileage, I would suggest that you verify your fuel gauge calibration is fairly correct at ¼ tank, as this would obviously help determine how far you can go before you start swearing.
You didn’t mention whether you had a carb or EFI, but increasing mileage through tuning might need another look.

Best,

[F500guy]

I have a MK3 with a SMB Ford ~310+hp (carb), T5z, 3.27 gears and stock Mustang gas tank (15.4 gal?). On an 800 mile trip some years ago, I was getting approximately 23.x mpg on some parts of the hwy. This highway is the 101 from San Jose to Huntington Beach, lots of different driving conditions. With the 3.27 and overdrive it reminded me of driving a boat, because you are cruising at such a low RPM on the hwy, like below 2200 on some stretches of the road.
Because we didn’t know where gas stations were located, we made it a point to stop and put gas in whenever we hit ~ ¼ of a tank. With your gas mileage, I would suggest that you verify your fuel gauge calibration is fairly correct at ¼ tank, as this would obviously help determine how far you can go before you start swearing.
You didn’t mention whether you had a carb or EFI, but increasing mileage through tuning might need another look.

Best,

Thanks, it is a carb, Holley 750 DP. I Can due some tuning for fuel mileage, The carb is not fully adjustable, so if I go to low on the primary main, I would need to drill out the power valve. Top of my list is a holder for my phone so I can easily map routes for such a problem. I reviewed some data for the trip and for the first time I used the "altimeter" data set, interesting for some data geeks to see why at some times I was closer to 13 AFR, climbing some hills!

[Skuzzy]

If I am going to go further than a gas tank will allow, for a round trip, and I am not familiar with the route, I will use "Garmin Basecamp" on my computer and lay out the route and mark the gas stations. I also check to make sure the gas stations are actually working stations, using "Google Maps". Then I upload the route to my Garmin and off I go. I also check and mark restaurants.

I do not expect to get much better than 18MPG with my fuel injected 427, TKX, and 3.31 RAR.

[Jim1855]

In years past I ran 3 - 4,000+ mile trips. Running interstate from MI to CO wasn't a problem. CO to MT could be questionable even on the interstate. Running 2-lane through MT (MT-200) was a problem, often had to slow down to better the fuel mileage just to make it to the next town. On a trip through WY the engine was stuttering on a slight uphill climb, found an Indian reservation with gas if you want to call 86 octane "gas".

Generally found that I could cruise for 2 hours, +/- 160 miles between stops, fluid in and fluid out, a bit of walking around and often a conversation or 2. Most days were 10 hours or so. That was usually enough.

Jim

[Dave Howard]

Gen1 Coyote with 490 HP tune. I was getting 23-25 miles per imperial gallon with the original 3.31 gears in the diff. Could easily go 4-5 hours between fill ups on long road trips doing a buck 20 on the metric speedometer and maintaining 2,000 revs.

[F500guy]

Colorado and Wyoming can be ruff. I was towing with my F150 headed east and about 1/2 thru my tank (36 Gal 400 mile range) I hit 40 mph head wind, dropped my mileage to about 9 MPG from 12. When I got to the station, I put 36.5 gallons in a 36 gallon tank. Cut that one a little close! Good ideal Jim, but some times when I get rolling I forget about time. So planning will be very important, moving up to the top of my to-do list the need for a phone mount!

[Blitzboy54]

306 got about 18 MPG, I don't have enough miles on the Coyote yet but early indications are about the same.