MPG drop towing small trailer

[kevdog0710]

I'll normally get 17-19 MPG for my 300 mile trek to Northern Michigan, with no trailer. I got 10.4 with the cruise set at 72 MPH towing a 10ft utility trailer hauling a Honda Pioneer SXS in 28 - 32 degree weather. Between the mesh gate, the height of the Pioneer, and its windshield, it is like pulling a parachute back there. I did lock out the 9th and 10th gears to keep the turbo from blowing so hard. I was getting around 9MPG in SE Michigan flatlands before I locked out those gears.

Locking out 9th gear was at least a 1 mpg improvement in my case. The turbos require richer fuel to avoid detonation apparently

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[DT444T]

Locking out 9th gear was at least a 1 mpg improvement in my case. The turbos require richer fuel to avoid detonation apparently

This seem to be a general consensus amongst the EcoBoost engine family. I have noticed that locking out 9 and 10 while towing a car gave me a slight bump.

It just kinda sucks listening to the motor rev to 2400-2600...

 

[notabot]

The turbos require richer fuel to avoid detonation apparently

You're 100% correct. Adding boost (air) without adding fuel is a no-no. Leans out the mixture and melts pistons.

 

[GEN14OWNER]

'22 Lariat 3.5 ext. cab, long bed, Max Tow package.

The other day I towed a 2 place ATV trailer with a 4' mesh swing up ramp with 1 ATV, total weight roughly 1500lbs. 65mph for the most part.
Driving the same route empty I get about 20.5 to 21.5 ish MPG...towing this small trailer dropped my MPG to 14.6mpg on the same route. I know towing a trailer will drop the MPG but 6-7 mpg for such a small trailer seems extreme.
For reference towing my flatbed car trailer with 2 ATV's and 2 weeks of hunting gear(4k+lbs total) my OLd Scout with a V-8 looses 2 mpg.
I'm a bit worried about what MPG I will get towing a toyhauler camper....

So how much (MPG or %) are you guys loosing when towing?

Darrell

I noticed a similar drop in MPG towing my single axle dump trailer. Then I tried switching to “Tow/Haul” mode just to see the difference and the “difference” was huge.

To my surprise, it held the gears a lot longer which I immediately assumed would rape my MPG but instead, I ended up only dropping about 2-MPG on the trip.

I was shocked!

But that’s with a RCSB 5.0 so this may be an “apples –vs- oranges” thing.

 

[Pedaldude]

Towing a 5X8 enclosed cargo trailer, I’m getting better MPG city. But then I totally change my driving habits and actually drive the speed limit.

This is with the 5.0 and using Tow/Haul mode.

A lot of automotive journalists and forum members disparage the aerodynamic qualities of bricks and barn doors but there are things even worse.

That steel mesh ramp is basically a perforated air brake like the one on this WWII dive bomber, which is designed to allow it to descend straight down under power:

 

[DT444T]

You're 100% correct. Adding boost (air) without adding fuel is a no-no. Leans out the mixture and melts pistons.

That's not what's being said. Of course you have to add more fuel with air, but at higher boost levels you must increase the Air/Fuel mixture even more than the typical 13.x-to-1 of an NA engine. Turbo motors run VERY rich under boost. And the more boost, the richer you run.

12:1 is perfectly reasonable at stock boost levels at WOT. Even when not at WOT there has to be enrichment for boost.

 

[notabot]

That's not what's being said. Of course you have to add more fuel with air, but at higher boost levels you must increase the Air/Fuel mixture even more than the typical 13.x-to-1 of an NA engine. Turbo motors run VERY rich under boost. And the more boost, the richer you run.

12:1 is perfectly reasonable at stock boost levels at WOT. Even when not at WOT there has to be enrichment for boost.

We're on the same page, my friend. IMHO, my generalization and your specifics match up OK.

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[darioa]

Over 13,000 miles towing a 5200 lbs TT with my 2021 PB, I get between 10 and 12 MPG, heavily dependent on speed, wind, type of gas (premium gets me 1-2 MPG better than regular), terrain, and altitude (on the coast I get 12+ MPG). I also lock the transmission to 8th gear (sometimes 7th) so the turbo boost does not come on as much (it uses much more fuel than the RPMs of the lower gears). I put the truck on tow mode when there is no way to get in electric mode.

 

[Calson]

With my GM diesel pickup the recommendation was to use Tow Haul mode only when the truck and trailer combined weight was 80% of the GCWR which in this case was with a 13,000 lb trailer load. Tow Haul changes the shift points and it also keeps the torque converter clutch locked longer before upshifting.

The faster one is driving the great the air drag and this increases with the square of the speed. A truck and trailer at 80 mph will have 4 times the air drag of the same rig at 40 mph. With a large profile camper I would keep my speed at 62 mph to maximize fuel economy.

If I drive faster to save 30 minutes over a distance of 250 miles then I do have to think about what that actually accomplishes as the truck will burn 30% more fuel and I will need to spend more time at places buying more gas or diesel.

 

[Ziggy73]

'22 Lariat 3.5 ext. cab, long bed, Max Tow package.

The other day I towed a 2 place ATV trailer with a 4' mesh swing up ramp with 1 ATV, total weight roughly 1500lbs. 65mph for the most part.
Driving the same route empty I get about 20.5 to 21.5 ish MPG...towing this small trailer dropped my MPG to 14.6mpg on the same route. I know towing a trailer will drop the MPG but 6-7 mpg for such a small trailer seems extreme.
For reference towing my flatbed car trailer with 2 ATV's and 2 weeks of hunting gear(4k+lbs total) my OLd Scout with a V-8 looses 2 mpg.
I'm a bit worried about what MPG I will get towing a toyhauler camper....

So how much (MPG or %) are you guys loosing when towing?

Darrell

Yes, what another member said. That mesh ramp is just like a sale even though it has air flow through it. Once I towed a trailer with a ramp up empty to pick up a car, after loading the car I got the same MPGs with a 5000 lb car as I did with the ramp up empty. As well as make sure you're locking out 9th and 10th. But most of it is that aero drag.

 

[RuggedGoods]

Like many people have already said, the 4' mesh tailgate is what kills your mpg. It's a huge parachute.

Take it off, leave it at home, and bring some basic ramps along in the bed instead, you'll get half your mpg loss back. Tow/haul mode is optional, see if you like the shifting patterns better, but lock out 9th and 10th gears in any case.

 

[Tall Tail]

Like many people have already said, the 4' mesh tailgate is what kills your mpg. It's a huge parachute.

Take it off, leave it at home, and bring some basic ramps along in the bed instead, you'll get half your mpg loss back. Tow/haul mode is optional, see if you like the shifting patterns better, but lock out 9th and 10th gears in any case.

How do you lock out 9th and 10th and why does this improve MPG's?

 

[Aron]

How do you lock out 9th and 10th and why does this improve MPG's?

On the gearshift are a "+" and a "-" button. If you tap the "-" button while in "D", it'll gray-out the 10th gear on the dash (and remove the gear from usage). Hit it a second time and it will remove the 9th gear from usage. Repeat as necessary. Reengage the gears with the "+" button.

The overdrive gears tend to rely on the turbochargers more than the other gears. It's the turbochargers, not the gears themselves, that reduce your fuel economy. You may need to lock out 8th and even 7th gear if you're towing a heavy load and you see that the turbochargers are being relied upon too frequently (say, in mountainous terrain) if you're trying to keep up your fuel economy (at the cost of speed and power, which happens when you lock out those gears).

 

[Tall Tail]

On the gearshift are a "+" and a "-" button. If you tap the "-" button while in "D", it'll gray-out the 10th gear on the dash (and remove the gear from usage). Hit it a second time and it will remove the 9th gear from usage. Repeat as necessary. Reengage the gears with the "+" button.

The overdrive gears tend to rely on the turbochargers more than the other gears. It's the turbochargers, not the gears themselves, that reduce your fuel economy. You may need to lock out 8th and even 7th gear if you're towing a heavy load and you see that the turbochargers are being relied upon too frequently (say, in mountainous terrain) if you're trying to keep up your fuel economy (at the cost of speed and power, which happens when you lock out those gears).

Interesting, i would have assumed higher gears would provide better MPG's.
Does this apply to the 5.0L (no turbo)?

 

[Aron]

Interesting, i would have assumed higher gears would provide better MPG's.
Does this apply to the 5.0L (no turbo)?

Good point; I forgot that not everybody has turbos. Without turbos, I agree that higher gears generally should be more fuel efficient...assuming that you can stay at those gears for long periods of time. If you're in the mountains, you might see a good deal of shifting between gears, so it might be more fuel efficient to remain in gears longer (which, as I recall, is what the tow/haul setting does, so this might be good enough).

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