Slowtrucker

So I tend to do about 1/3 of my driving as longish distance towing an enclosed cargo trailer with my 2017 EB. I have noticed that I generally get around 17.8 to 19.7 mpg when driving around - with almost all trips being 15 to 20 miles. However when towing the trailer, I tend to get around 8 mpg. I tow in Texas where the speeds are 70+. Yes, I do know and have noticed that if I drive at 50 I get substantially better mileage but I don't think the potential for bloodshed is worth that savings in gasoline.

All of those numbers are with 10% ethanol in my 83 octane gasoline.


I an pretty sure from reading here that the difference in cost of premium and regular does not offset the cost difference, with or without the towing issue.

So here is the question.


I am considering using ethanol free gasoline when traveling to get more miles between fill ups however the range increase needs to be substantial to offset the around an extra $.50 per gallon cost. It is not when not towing.

Has anyone tried running alcohol free gasoline long enough to develop viable numbers? With and without a trailer tow.

Napalm

one I have to point out that your name is slowtrucker. so you should be going 55 if only becasue of name.

Now do you mean to say 93 octane gas your post says 83 and that would run funny.

I've done some checks to show that running ethanol free in my area, in my cars, doesn't pay for itself. My price difference is a bit more however at closer to 80 cents more per gallon. And worse few stations provide it in 93 octane. 2 of my cars only drink 93. But again even at .50 per in difference I don't know that it would matter so much.

but I'll also say this - have you considered a more aero dynamic trailer or making some truck bed cover/fairing for when you tow. I suspect that's the biggest issue you have - is the aero drag at 80 with your tailer is costing you a lot. fuel won't help that really.

when you tow are you in tow mode and does it stay in say 8th when you tow on the highway or lower?

I would absolutely keep 93 octane in there especially in the summer - I do the same here. but I don't know that pure gas will help you much if at all. Maybe try a tank or 2 and see where you end up. won't hurt anything.

Davesp

I'd recommend you slow down but not necessarily to 50. Aero drag is your enemy if turbulence is generated, drag force is proportional to the square of relative flow velocity with respect to the object. Try 65 mph and certanly not over 70 mph.
Also have a look here: https://www.edmunds.com/g00/fuel-eco...8%3d&i10c.dv=7

Slowtrucker

Thanks for the comments.

Can't pull a fast one over you! The name was to mask my activities. How did you know I travel at ~80?


No, I probably meant 87 but was on the phone with someone else as I typed.

The trailer is as aerodynamic as I could get - V nose with a droop and I have added some devices (look up AirTab fuelsavers) that create turbulence behind the trailer - reducing drag. Very careful actual testing showed that they increased mileage 3%. I have a bed cover and it almost always stays in whatever gear it can attain - 8th with a rare foray into 9th if we are going downgrade. No I don't use T/S as it markedly cuts into mileage.

You are probably right about the price spread, I was thinking of when I buy mower gas (ethanol free) instead of going to a box store and paying $20 a gallon for it. I will check that when I pull out of here in the morning.

I don't care about around town normal regular usage so I am not really inclined to buy a tank and try the ethanol free stuff (I have only seen it at 87 - not 93). However if it improves the mileage on the highway more than 10%, it might be a winner 9 versus 8 on a 36 gallon tank is a ways.

tvsjr

Ethanol-free isn't going to pay you back. Unfortunately, you're towing a big sail around and doing it at high speed. Lots of energy consumed, lots of turbo spool. When the turbo gauge goes right, the gas gauge goes left... quickly.

If you're towing that trailer frequently, a spoiler on top of the cab to help direct air up and over the trailer (versus pulling it straight into a brick wall) may help you.

Ricktwuhk

Many trailer tires are not rated to drive 70+...

93 octane should allow better towing (see the manual), but 8 mpg is not out of the norm, especially at high speed. Ethanol free will never pay back.

blkZ28spt

What mileage do you get at various speeds between 50 and >70? Like, 60, 65? Towing a trailer at high speeds seems like a high "potential for bloodshed" anyway...

Slowtrucker

Thanks. Er..how to make a good truck look funny! I will seriously consider that but with a V nosed trailer and the front end slope, I question the efficacy of a spoiler on the cab of the truck. Maybe time for a test...wonder if I can rent one for a weekend trip.

The reported 3% improvement with AirTab stuff - was the results two runs of around 100 miles each in both directions on the same day in the same weather from and to the exact same place (within 5 feet) with the same trailer and tow vehicle to gather the differences. First run without them, second run with them on cruise control to keep the speeds as close to the same as possible. The results impressed me, so I made a permanent installation on this trailer also as the test trailer was a 6x12 and this one is a 7x14 (and 6" taller). I can get all sorts of wordsmith answers from folks on the internet, but really prefer facts that are repeatable, testable, and verifiable. I suspect the AirTab stuff may also minimize the impact of a spoiler, but we shall see.


According the the tire speed rating chart MY trailer tires (M) are good to 87 mph which is well above the speeds I drive at. I guess that also means many slow drivers actually spend their lives in total fear of what might happen.

Your comments about octane and ethanol free are very interesting as I suspect they may even be accurate. However, can you tell me if they of the same class as your tire speed warning or the results of some actual testing?

Slowtrucker

Lets start out by saying that 95% of all my towing is at highway speeds, whatever that happens to be. Towing at much lower speeds when the rest of the world is doing 75+ just plain scares me, but I am a known coward. However, that is not saying I have not towed slowly, just that it is vary rare. However between 60 and 65 I seem to get around 9 mpg IIRC.

I wonder why all the know it all's seem to get hung up on having me paint target on the rear of my trailer by driving around 50% of the speed of traffic?

I am SURE your mileage varies a lot!

mikeinatlanta

I don't have the formula, but google is your friend. There is a definite increase in energy per unit volume with E0 vs E10, and if my memory is correct is a bit less than 3%. Every time I have seen the math run it would require about 3% or less price difference to pay off.

Unlike the variances when changing from 87 to 93, E0 vs E10 is straight up math and the engine, towing, or aerodynamics are irrelevant.

One factor here that I haven't seen posted is that in most areas E10 can be had in 93 and E0 tends to be 91. That alone may cost some power and mileage in a modern Ford motor.