Highway MPG

[dlunior]

So my wife and I have owned the 2014 Ford Fusion Hybrid SE for a year now. I cant seem to get the MPG over 33-35 driving long distances on the highway. I live in Florida, the biggest hills I see are overpasses. I've trying to set the cruise at various speeds 65, 70, 75. Same results. It not till i hits 60-62 do I get the 40+s. Local in town driving 45+ is easy to obtain. Just dem pesky interstates giving sad mpg faces. Something I am doing wrong, just the way it is, or something to get checked out?

 

Thanks

 

D

Edited July 20, 2015 by dlunior

[murphy]

Air drag increases with the square of the speed. You will not get good mileage at high speed.

[Griswald]

Here is my last 175 mile trip on interstates at 70 - 73 mph with cruise set and 2 adults with luggage...Don't tell me you can't get good mileage at speed.

[hybridbear]

So my wife and I have owned the 2014 Ford Fusion Hybrid SE for a year now. I cant seem to get the MPG over 33-35 driving long distances on the highway. I live in Florida, the biggest hills I see are overpasses. I've trying to set the cruise at various speeds 65, 70, 75. Same results. It not till i hits 60-62 do I get the 40+s. Local in town driving 45+ is easy to obtain. Just dem pesky interstates giving sad mpg faces. Something I am doing wrong, just the way it is, or something to get checked out?

 

Thanks

 

D

Which wheels & tires do you have? The 18-inch Goodyear tires have higher rolling resistance and get 10-15% worse MPG than the standard 17-inch tires. Air conditioning also reduces MPG.

[lolder]

You ought to be able to get more than 40 mpg at 70 mph in warm weather after the AC has cooled the car down. If you go faster, the mpg penalty is 6 mpg per 10 mph. check your tire pressure and make sure it's above the door sill number, 40psi is a good number.

Tires and pressure can be almost 5 mpg, speeding 6 and heavier AC us ~3.

[jeffo65]

Last month we got 38 mpg with two bikes on the bike rack (hitch mount) during a 550 mile road trip. Without the bikes we can easily obtain 40 mpg over a longer road trip. And we are running 18" wheels with the Goodyear tires.

[nv rick]

Being in FL, the use of a/c could have an effect on your mpg. I have a '14 MKZ-h, which generally gets worse mpg than the Ford Fusion hybrid due to weight difference and tire size. However, I still manage hwy mpg in the high 30's-low 40's. Around town, I've seen mid to upper 50's.

I am getting the above mpg's lately with the daily high temps above 100 degrees and the a/c set at 72 degrees.

I live west of Las Vegas. When going to LV, my typical mpg is around 42mpg. Coming home, it is generally around 38mpg. Between home and LV, there is about a 3,000 foot elevation change, and the change from LV to the Mountain Springs pass is even greater. The majority of the highway is 70mph on the west side and 65mpg on the east.

On a recent trip to WI, with four adults and luggage, we averaged about 36mpg. Most limits west of the Mississippi were 70 or 75mph. In Utah, the speed limit was mostly 80mph. I generally drive about 5mph above the limit on long trips.

I would expect that with the lack of elevation change in FL, you should average way above what you are getting.

[Griswald]

This was during the 175 mile trip I posted about. Just outside Columbia SC. 103 degrees while moving 73 mph. We did see 106 for a minute or so. So, yes, my AC was running strong.

[milleron]

That's strangely low hwy mileage for a broken-in FFH in my experience. Your best hwy mileage will never be as good as your best mileage in suburbia where you can keep speeds of 40-50 mph for fairly long distances, but it should be easy to do better than 35. I have brutally long and fairly steep upgrades on the Interstates I frequent, and I can get 40-46 mpg without doing anything other than trying to keep it out of EV so that the SoC remains as high as possible. Put the tires up above 40 psi, go as slowly as you can without allowing it to lapse into EV mode often or for long, and try to avoid changes in speed. The latter can be impossible on busy interstates, but try. I've found that 65 mph will keep the car in ICE mode almost all the time but it's necessary to nudge up to 67-69 mph on some downhill stretches. My opinion after 17K miles is that FFHs have no business operating in EV at Interstate speeds, but the PCM reprogramming of 2013, unfortunately, does allow it. At those speeds, I can see a near 100% charge of the HVB depleted in 1/3 of a mile. Then your instantaneous mileage goes down to 20 while the poor ICE labors long and hard to get the state of charge back to a level that frees it to expend all its energy on propelling the car. On the freeway, you'll probably do best by limiting the HVB to assisting with uphills and acceleration, as opposed to letting the car operate in EV mode. (In town, you want to be in EV as much as possible without depleting the state of charge badly.) I'm not sure what's critical with SOC, but I try to prevent mine from going much below about 30% in town. On the freeway, I strive to keep it way up there around 90%. If those measures don't give trip mileage above an average of 42, at least in weather that doesn't require AC, then I think you're right in wondering of "something's wrong." However, if you're really having little trouble getting above 45 in town, the car is probably OK.

[lolder]

The mpg's really start to take a hit at temperatures over 95. You just didn't notice it as much in a car that got 20 mpg. The ACs all take the same energy regardless of the drive train type.

[dlunior]

The wheels are in fact the 18" Goodyear Eagle LS2. They are inflated to 34 psi per the sticker in the door frame. Should I increase the psi to 40? Ford says they see nothing wrong :-/

[machoman1337]

I can never break 40 mpg on the freeway, and that's during the cooler parts of summer in BC/Washington. Right now there's a heat wave and running the A/C makes my fuel economy as bad as it can possibly get year-round (our winters are mild so I almost never have to run the heater). I would expect to get low 30s in freeway driving with the A/C blasting.

 

Also maintaining a steady speed vs frequent acceleration/braking makes a big difference. Use the cruise control as much as you possibly can.

 

Don't bother inflating the tires unless your tire pressure monitor tells you to.

[hybridbear]

Don't bother inflating the tires unless your tire pressure monitor tells you to.

I wouldn't ever wait that long. A tire must be seriously under inflated before the TPMS alert sounds.

[hybridbear]

The wheels are in fact the 18" Goodyear Eagle LS2. They are inflated to 34 psi per the sticker in the door frame. Should I increase the psi to 40? Ford says they see nothing wrong :-/

I'd try 40 PSI. Maybe even 44 PSI. That's where we keep our tires in the summer. How much tread life do you have left on them? When it's time to replace them a few forum members have found the tires that seem to deliver better gas mileage than the LS2 tires.

[corncobs]

I wouldn't ever wait that long. A tire must be seriously under inflated before the TPMS alert sounds.

I agree with that when my alert sounded my tire pressure was down to around 20 psi.

[dlunior]

The tires are still new-ish with only 15000 miles on the car. I'll try to increase the PSI to 40 tomorrow, got a decent highway trip coming up and see if it helps any.

[higheroctave32]

This is the end result of our recent vacation. We went from Sacramento to Vegas, spent 4 days there, then drove to San Diego and spent 2 days there, then back to Sacramento. I was rarely driving less than 75 and the air was on probably 95% of the time. 2 adults an 11 year old and the trunk stuffed within an inch of bursting and half of the back seat as well. A little basic hybrid driving behavior tweaks makes all the difference

Edit: I did do my best while on the freeway to keep the ICE in charge of propelling the car. There were many long stretches of flat road where my instant MPG was showing 60 and above. 70-75 air con running.

Edited August 6, 2015 by higheroctave32

[ptjones]

The tires are still new-ish with only 15000 miles on the car. I'll try to increase the PSI to 40 tomorrow, got a decent highway trip coming up and see if it helps any.

Try 50PSI instead like I have been doing for around 80K now, remember the Michelin's have a max PSI of 51 when cold. :)

 

Paul