Tow Speed

[Cam A]

I tow at 90 Kmh (54-ish Mph) as much for the view and pace as the mileage. If the trailer is on behind, it's time to put yourself in a vacation frame of mind and enjoy the scenery.

[Frederick L. Simson]

Originally Posted by Raya L.

1000 rpm seems really low to me, but then I suppose each vehicle is different. I guess it's something to check for your own vehicle.

I must admit 1000 rpm is a very rare occurrence, only when going slightly downhill or on the flat when the engine is just maintaining momentum. I once noticed it while crossing the low desert on a long trip. The next gas stop indicated 18 mpg for that segment, the highest I ever experienced while towing.

Much more common for me is in the 1500 to 2500 range, with a 15.9 mpg average.

[Frederick L. Simson]

Originally Posted by Cam A

I tow at 90 Kmh (54-ish Mph) as much for the view and pace as the mileage. If the trailer is on behind, it's time to put yourself in a vacation frame of mind and enjoy the scenery.

I wholeheartedly agree with that.

[Cam A]

It seems to me that best mileage occurs at the torque peak for your motor; whether this applies for towing, I'm not sure.

[floyd]

Originally Posted by Barrie Bochoff

I wondered the same thing. To find out, I bought a Scanguage II. (No association; about $150.). It connects to your OBD2 port under the dash on all cars 1995 and newer (just a straight plug in). It shows four data items at a time, which can be changed, including current MPG and average MPG. You can switch between reading for the trip, tank, today and yesterday.
Basically, the slower you go, the better the MPG. I have a manual transmission and I wondered if it's better to downshift and when; downshifting burns more gas.
When on the interstate, I try to stay around 55 if I'm not holding up traffic. If I'm planning a long trip, I use a spreadsheet I made to determine what my costs will be a various average speeds to help me decide if the extra time it will take me is worth the savings.
Good luck!
Barrie

Heck, we only use "speadsheets" at night when the rig is not moving at all! [also have good stabilizers]
25O thread count is usually more economical, but 600 thread count is worth the difference!

[Byron Kinnaman]

Originally Posted by floyd

Many TVs are designed to run the air conditioner in several settings, including those which involve "defrost". The air conditioner can adversely affect fuel econmomy, to varying degrees, If you don't need it on don't run it.

Preemptively....<_<
Yes, I have heard the data on rolled down windows and air conditioning.

Frederick;
Another guage which used to be common and installed for watching fuel consumption is the Vacuum guage.
The thing worked pretty well, but it was distracting, tedious and annoying when used properly.{lol}

A number of years ago somebody did some research and testing on A/C vs open windows vs gas mileage. If my memory serves right it was better to have the windows up and the A/C rather than fight additional drag caused by open windows.

Also the way you drive has a big effect.

Byron

[Cyndi B.]

God help you all in you get in front of me.

[Raya]

Originally Posted by Byron Kinnaman

A number of years ago somebody did some research and testing on A/C vs open windows vs gas mileage. If my memory serves right it was better to have the windows up and the A/C rather than fight additional drag caused by open windows.

I think a lot depends on the specific car/shape. I know for my car, the AC on and the windows up clearly makes for worse mileage than driving with no AC and the windows down, but then I don't have a "used bar of soap" shaped car I suppose the more aerodynamic your car is, the more the windows-down might make a difference over the AC.

[Lee Senn]

Originally Posted by mcbrew

To add to my previous post: I got about 23-24 MPG towing our 13' Scampup to Gettysburg last weekend. This was our first trip with it, so I don't have that much experience. There are nothing but hills between here and Gettysburg. These aren't mountains (okay, they were a few million years ago), but a few hundred feet up and down, over and over has an impact on fuel economy.

In just under two weeks, we'll be taking a trip to Maryland's eastern shore for a weekend of camping. This is a much flatter drive. I hope to get 1 or 2 MPG better on this trip. I'm not all that disappointed with 24 MPG, but I wouldn't mind better fuel economy!

mcbrew What are you towing with? I want one !! Lee and Norma

[floyd]

Originally Posted by Raya L.

I think a lot depends on the specific car/shape. I know for my car, the AC on and the windows up clearly makes for worse mileage than driving with no AC and the windows down, but then I don't have a "used bar of soap" shaped car I suppose the more aerodynamic your car is, the more the windows-down might make a difference over the AC.

My point was that running the air conditioning costs a more than not running it. sometimes as much as several MPG.

[Chester Taje]

Originally Posted by floyd

My point was that running the air conditioning costs a more than not running it. sometimes as much as several MPG.

Some info here.
Does Running Your Car's Air Conditioner Really Affect Gas Mileage

[Raya]

Originally Posted by Byron Kinnaman

A number of years ago somebody did some research and testing on A/C vs open windows vs gas mileage. If my memory serves right it was better to have the windows up and the A/C rather than fight additional drag caused by open windows.

Byron

Originally Posted by floyd

My point was that running the air conditioning costs a more than not running it. sometimes as much as several MPG.

Hi Floyd,

I was referring to what Byron said - guess I should have quoted him. Sorry!

[Alf S.]

Hi: All...There's an old "Newfie" saying..."The faster I go the behinder I get". I think that applies to MPG and trailer tuggin'. 19.5 miles per. Canuck gal. towing an Escape 5.0 on the trip to Niagara Falls and back taint bad!!!
Alf S. North shore of Lake Erie

[floyd]

Originally Posted by Chester Taje

Some info here.
Does Running Your Car's Air Conditioner Really Affect Gas Mileage

20% of 25MPG is 5mpg.

[Chester Taje]

Originally Posted by floyd

20% of 25MPG is 5mpg.

I believe if you read it correctly, it said in some vehicles, not all vehicles.

[mcbrew]

Originally Posted by Cam A

It seems to me that best mileage occurs at the torque peak for your motor; whether this applies for towing, I'm not sure.

Peak torque on my car is at 4,400 RPMs... I can tell you for sure that I don't get great fuel economy in that RPM range.

Many people do not realize that there is a big difference between greatest thermion efficiency and greatest fuel efficiency. Thermal efficiency is getting the most work out of a given amount of fuel. Fuel efficiency is getting the most miles per gallon of fuel. You don't necessarily need a lot of horsepower at the wheels to keep rolling down the road. The engine might not be at its most efficient, but you can be using less fuel.

[Byron Kinnaman]

Originally Posted by floyd

20% of 25MPG is 5mpg.

When I read the whole article it repeated what I had said earlier. You're better off with the A/C than with windows open.

[mcbrew]

Originally Posted by Lee Senn

mcbrew What are you towing with? I want one !! Lee and Norma

Sorry, missed your question until now. I tow with a Scion xD. It is a subcompact car made by Toyota which shares components with the Yaris, Corolla, and Matrix.

I just drove back from Gettysburg again today, but without the Scamp. I got home with 47 MPG in the display, which is more like 44 MPG in reality. I do calculate every tank at the pump. I won't end this tank with MPG that high... probably closer to 40 MPG once I get back into my normal commute.

So, 24 MPG towing a Scamp sounds good, but it is a LOT lower than what I usually get. My last tank was about 38 MPG, but that included some higher than normal highway speeds. My mileage really drops off above 60-65 MPH.

[Kurt G]

I think something that has been missed in the aerodynamic issue in that your TV is punching through the air, your trailer is either also pushing through the air as well or slipping into the pocket that your TV creates. This all depends on the height and shape of the TV. Tie a piece of yarn to the rear roof section of your car and watch what it does while pulling your trailer and at what speeds, this will give an indication of what the air coming off the TV is doing and where it is going. With my forester the sweet spot to get the airflow to run off the roof and up over the trailer without rotating and getting caught up between the TV and the trailer is just north of 60, I can actually feel it when I get it in the "sweet spot".

[Cyndi B.]

Hey, you are pulling a trailer.