FORD CMAX driving for MPG's, Aero Mods and Hypermiling

[ptjones]

My 155k mi Fuelly.com average on my CMAX is 47.8mpg

Paul

[aerostealth]

It is not worth the extra cost. I use a higher grade octane in our Ford F 150 XLT 4x4 3.5 L EcoBoost in preparation to tow our 5th wheel trailer. This is recommended by Ford. Since we have a 36 gallon tank and tend to refill it at the half tank level I will put 91 octane in just to get to 89 octane when the gasoline mixes. When we return we refill with 87 octane.

[S Keith]

Originally Posted by ptjones

Minimum octane for CMAX is 87, max ethanol % is 15 and regular in NM is 86 octane, I use Premium 93-91 octane.

Paul

That's done because lower air density means 86 at altitude is equivalent to 87 at sea level. It's a non-issue.

Originally Posted by ptjones

Premium is worth 1-2 mpg for me, not quite worth the extra cost, but I like the extra range I also have 2016 F150XLT SC 4x4 2.7L EB with 23.3 mpg mostly HWY 15k mi., with 36gal tank, I use regular.

Paul

Unless you derived that difference scientifically, it's likely all in your head. The anti-knock agents in higher octane fuels contain less energy, i.e., Premium gas has less energy per gallon than 87. It's not a big difference, but it's there.

You're basically claiming that by burning a more expensive fuel with less energy content, you are getting better gas mileage. Unless your vehicles are adapting their compression ratio to take advantage of the higher octane fuel, which is generally not possible unless they're somehow changing stroke, bore or valve lift/duration to compensate.

[ptjones]

Originally Posted by S Keith

That's done because lower air density means 86 at altitude is equivalent to 87 at sea level. It's a non-issue.



Unless you derived that difference scientifically, it's likely all in your head. The anti-knock agents in higher octane fuels contain less energy, i.e., Premium gas has less energy per gallon than 87. It's not a big difference, but it's there.

You're basically claiming that by burning a more expensive fuel with less energy content, you are getting better gas mileage. Unless your vehicles are adapting their compression ratio to take advantage of the higher octane fuel, which is generally not possible unless they're somehow changing stroke, bore or valve lift/duration to compensate.

I actually did test this with my ScanGaugeII, I monitored Ignition timing and here is Link to fordcmaxhybridforum starting with Post #32 the ECM advances timing for the octane of fuel: Bought Ethanol Free - Page 2 - General Discussion - Ford C-MAX Hybrid Forum
As you can see I gained at least 2+ mpg from going from Regular to Premium and with Octane Booster another 2mpg. Sure is nice having a ScanGaugeII to monitor ICE and HVB functions.

Paul

[ptjones]

My Fuelly average is upto 48.4mpg with 174k mi. and have been averaging 53 mpg for around a year and a half now.

Paul

[ptjones]

Haven't been here in a while, with 212k miles my Fuelly.com average is up to 49.2 mpg and still climbing.

Paul

[Daox]

Very nice!

I've been keeping my eye on the energi models... their price is all too reasonable these days.

[ptjones]

I would like to also, but I'm not giving up my Hybrid until it dies. My 90 day average is about 54 mpg with 14 fillups and ten thousand miles and mostly HWY. Getting 59 mpg City.

Paul

[Daox]

If you're doing that much daily driving with the car, the energi model won't do a ton of good for you anyways unless you have frequent opportunities to charge up during the day.

[ptjones]

You are right about that, was mostly thinking for around town when I'm driving 40-100 miles in a day.

Paul