MPG!!

[Neurobit]

Anything over 70 and your MPG is going to drop through the floor as the cylinder deactivation won't kick in, so 16-17 on the highway, especially in a more rolling area like NY, is to be expected imo.

^^^ This ^^^

 

[Twoamen]

MD to New Hampshire. Average speed 65. Mpg average 19.5.... Now the weird part is all the new changes 2019 received I got 22.5 on same trip with 2014 Limited

 

[Kasey]

Thanks. Your mpg certainly seems low compared to others with 4WD and 3.21 gears. The Hwy mpg suffers at speeds over 65. I would think 19-20 would be typical at 75. 16 mpg is low.

My only thought would be to hand calc your MPG. On your next trip, top off the tank until it's full to the fill neck, reset the trip meter, and drive as economically as possible at highway speeds. Run a half tank through if possible for greater accuracy. Fill up to the same level as before, record the gallons to fill from the pump, and divide that into whatever your trip meter mile are. It may be that your mpg readout is off. It should be close. If the hand calc mpg is higher, see your dealer.

If it is the same or close, here are a few things to examine.

1. Alignment. Check for uneven tire wear. You can feel sharp edges on either the leading ot trailing edges of the tread by running your hand across the tread. All edges in the tread pattern should feel the same. If your truck is out of alignment, rolling resistance is increased, tire wear is accelerated, and mpg's suffer.

2. Tire pressure. Make sure tires are inflated to the max recommended pressure listed on the sidewall. Low.pressure can cost you several mpg.

3. Fuel. If you are running a high ethanol blend, you will not achieve the rated mpg. Ethanol has less energy per gallon than pure gas. It may be hard to find pure gas in your state but avoid fuels with higher blends if possible.

Those are the things I'd check. If all of that checks out, I'd definitely document those things and your hand calc test and see the dealer. It is possible that a faulty engine sensor can cause the engine to run rich. I've had MAF and oxygen sensors do this. They can be faulty when new.

Good luck.

Thank you very much for the detailed response!! I will try at 65MPH or less. Someone else posted that the cylinder deactivation does not work at higher speeds. Do you know what speeds it stops working at??

BTW, the truck is brand new so although alignment could be off, no time for excessive tire wear yet.
Tire pressure is 36psi when cold so I'm good there.
Not running hi-ethanol fuel.

 

[Kasey]

Anything over 70 and your MPG is going to drop through the floor as the cylinder deactivation won't kick in, so 16-17 on the highway, especially in a more rolling area like NY, is to be expected imo.

Hmmm.....At what speed does the cylinder deactivation not work??

 

[Neurobit]

Hmmm.....At what speed does the cylinder deactivation not work??

Not sure about which speed, but pretty much if your Eco light is on (in your center cluster), it's a pretty sure sign that MDS is active.

 

[Twoamen]

Tire pressure 38 raised to 43 at highway speeds.
Alignment last month with Level kit installation.
Always 89 Octane on fuel.

 

[Twoamen]

275 60-R20 Michelin Defender

 

[Rustydodge]

Hmmm.....At what speed does the cylinder deactivation not work??

Whenever wind resistance gets high enough that it needs to be in V8 or you're going uphill.

And none of these numbers mean anything unless you are hand calculating them, every tank.

Took my first long road trip with my 4th gen that has 3.92 diff. When running 70-80 i could stay in 8th speed, 2000ish rpm, and occasional MDS. When running 80+ (traffic was really moving after labor day) the truck actually downshifted to 7th and ran 3000ish rpm, never in MDS. EVIC listed mid 16s while hand calculated was 17 MPG. I think average speed per that take was 68 MPH.

You should definitely expect lower MPGs when going above 65 MPH. Wnd is a huge factor

 

[Neurobit]

And none of these numbers mean anything unless you are hand calculating them, every tank.

^^^ This ^^^

You are spinning your wheels until you get an accurate number. Do this first and let us know what your true consumption is.

 

[ExcursionDiesel]

There is no definitive answer on when MDS deactivates. It's purely based on engine load. On uneven terrain, the weight of the truck matters. Headwind vs tailwind matters. Oversized tires and lift kits increase the load also.

I would be surprised if MDS activates at 80+ unless you're going down a hill or had a 15-20 mph tailwind!

 

[Neurobit]

There is no definitive answer on when MDS deactivates. It's purely based on engine load. On uneven terrain, the weight of the truck matters. Headwind vs tailwind matters. Oversized tires and lift kits increase the load also.

I would be surprised if MDS activates at 80+ unless you're going down a hill or had a 15-20 mph tailwind!

Exactly.

 

[bwmatthews]

Did a trip weekend before last that was a little over 500 miles round trip and had 19.9 MPG Averaged 65 most of the way with some around 70. I was glad to see that. Now I just have to get my boat behind it and see how it does.

 

[356]

On a 220 mile trip with a slight headwind I average 21 mpg on the cluster readout at 70 mph. About 20% was in the city.

 

[craigrh13]

4x4 crew cab 3.21 rear end and my mileage sucks. 18.5-19. I’m used to my 2015 5.0 f150 which always got 20-22 on the highway and had quite a bit more get up and go.

 

[Celtic Sun]

Bought my truck in Charleston, SC. Drove it home to Aiken, SC and did 85 mph the whole way home on I-26/I-20. The MDS stayed on for quite awhile when cruising, only going off occasionally when it shifted to a lower gear to climb inclines.

Btw, is it normal to hear a small clunk when the MDS turns off and the other 4 cylinders are activated?

Also noticed, my truck does not like going slow and being in the low gears. May be just my imagination though.

 

[392DCGC]

Bought my truck in Charleston, SC. Drove it home to Aiken, SC and did 85 mph the whole way home on I-26/I-20. The MDS stayed on for quite awhile when cruising, only going off occasionally when it shifted to a lower gear to climb inclines.

Btw, is it normal to hear a small clunk when the MDS turns off and the other 4 cylinders are activated?

Also noticed, my truck does not like going slow and being in the low gears. May be just my imagination though.

MDS 4 cylinder activation is usually very dicrete since it only happens once minimal load is on the engine. I find MDS deactivation much more noticeabe, particularly if you are gradually increasing throttle - there's a noticeable change in exhaust/engine tone from high 4 cylinder load to activating all 8 cylinders.

 

[SpeedyV]

MDS 4 cylinder activation is usually very dicrete since it only happens once minimal load is on the engine. I find MDS deactivation much more noticeabe, particularly if you are gradually increasing throttle - there's a noticeable change in exhaust/engine tone from high 4 cylinder load to activating all 8 cylinders.

I hear it turning on and off, but it’s very muted...almost like a torque converter locking and unlocking.

 

[MTRHEAD]

OK, well, I'm now perplexed. I just took delivery of a 2019 Limited with eTorque 5.7 Hemi and I am getting HORRIBLE MILEAGE!! To test and make sure it wasn't me, I got on the highway, set the cruise and reset the trip AND the average fuel economy screens and am getting only in the 16s (drove for approx 40 minutes). How is this possible?? Brand new truck that is supposed to be getting 22 on the highway and I'm getting mid-teens? I'm certainly open to any ideas but I'm about to head back to the dealer to see if they can figure this out. Other than this issue, the truck is great! Ideas??

One possibility is fuel. The ford dealer at a town near me was having complaints of poor fuel mileage on several vehicles . They found that they were all buying fuel at the same station and went and checked it. The station advertised 10% ethanol and it tested at 22%.

 

[356]

For every 10% of ethanol, mileage goes down 4%. At 16mpg on good 100% gasoline, a typical 10% blend gives 15.36. If you use 15%, which is pump gas here in Missouri, you get 15.04.

My current 20.7 would be 21.94 if we had 100% gas.

 

[Dkwatts1522]

Milage update after 3 months of ownership and 6370 miles. The truck lifetime is 17.8 mpg with 221 hrs and average speed of 28.08 mph.