Efficiency Help

[RickLightning]

I'm not trying to start an argument - I'm genuinely curious if my understanding is incorrect...
I know extreme over/under-inflation can cause uneven wear, but apart from the extremes it was always my understanding that lower pressure gives a softer ride, and higher pressure gives more efficiency (harder tire -> less rolling resistance). So you just need to find your personal preference in the tradeoff. I don't give too much consideration to the door sticker recommendation because that value is designed to maximize softness for stock tires. My rule of thumb has always been to inflate somewhere about halfway between door sticker recommendation and max PSI printed on the tire. (Unless max is something like 80 PSI, in which case I don't do the halfway rule.)

Change my mind.

I was making the point that the factory sticker for the AT tires is 36, while the non-AT tires are 42. You can inflate tires to anything you want, as long as the cold pressure doesn't exceed the sidewall pressure.

Many people don't check their tires regularly. A tire at 36 pounds in winter can easily be in the mid-40s in summer. I check mine monthly. TPMS is not a tire gauge.

Some prefer to do the chalk test.


Instructions

1. Fill the tires to a good starting pressure. If you are unsure what pressure to start with then subtract 10 percent from the manufacturer's maximum inflation pressure on the side of the tire. If, for example, the maximum is 40 psi, then 10 percent of 40 is 4. Subtract the 10 percent value from the maximum psi value. So, 40 - 4 = 36. Use 36 psi in your tires. You could also use the following calculation for the starting pressure.
   • Weight of vehicle / (Manufacturers weight rating x 4)) x Manufacturers inflation pressure at weight rating
2. Drive to a flat area. This can be your driveway or the street in front of your house. Just make sure there aren't a lot of cracks, bumps or pot holes in the ground.
3. Using chalk, draw a thick, straight line across the width of the tire.
4. Use Test Variance 1 or Test Variance 2 for the completion of the instructions.

Test Variance 1

1. Drive the truck forward at least one-full truck length.
2. Inspect the chalk on the ground. A tire with the proper air pressure should press the chalk line evenly across the ground. This means you'll see the entire chalk line imprinted on the ground. If your tire is over-inflated, you'll only see a small portion of line in the center. If you're tire is underinflated, you'll see only the sides of the lines since the middle of the tire is not making contact with the ground.
3. Adjust your tire's air pressure according to the chalk test results and try again until you get the chalk line to press evenly across the ground.

Test Variance 2

1. Drive the truck to the end of the street and back or around the block.
2. Inspect the chalk on the tire. A tire with the proper air pressure will show the chalk evenly worn across the tire. If your tire is over-inflated, the center of the line will be worn more than the edges. If you're tire is underinflated, the outer edges of the line will be worn more than the center.
3. Adjust your tire's air pressure according to the chalk test results and try again until you get the chalk line to evenly wear across the tire.

Over-Inflated = More wear on the center of the tire = center of chalk line visible on ground = chalk line worn more in center

Under-Inflated = More wear on the outer edges of the tire = outer edges of chalk line visible on ground = chalk line worn more on outer edges

Sponsored

 

[Green1]

I think the point on the tires though is that, if anything, his are over inflated, not under. And over inflated tires do not hurt range, and may even help (at the expense of a harsher ride and more/uneven tire wear, and worse road holding)

I do know that AT tires are noticeably less efficient than HT tires, so that will be impacting some, the rest is hard to pin down. Probably driving style, terrain, weather, but very difficult to be sure. It is almost impossible to compare different drivers in different trucks on different roads in different weather in different parts of the world and come to any conclusion about why one person might be getting better or worse economy than the other.

 

[Ragman]

There’s a F150 range extending song you need to learn it goes “I drive 55…”

Your range is typical from my experience (have 3 different lightnings) all are comparable - only truck related difference is one has a headache rack/light bar and winter tires both kill range.

The other range killer is temperature - there is a point between 10-15 Celsius external that battery heating must kick in.

Today at 15C and 100 km running at 27kw/100. Same drive last night 33kw/100 at 8C. Distance of 300km each way.

Same 300 km at -30C is 48kw/100.

I now set departure's anytime temp is forecast below 10 Celsius for that drive

 

[Bokenator]

I have an ER Lariat with the same Hankook AT2 tires as original poster. I also have a tonneau cover and mud flaps. My tires are inflated to 36 per door jam sticker. At about 70 mph, I average 1.9 -2.0 miles/kWh.

For comparison, I usually get around 2.3 around town. I've gotten as much as 2.2 following a semi at 75 mph at the minimum follow distance with hands free driving or adaptive cruise control set. I've gotten as low as 1.7 on a windy day attempting to maintain 75 mph. I've gotten 2.3 driving county roads at night(not interstate) at 63 mph, where going faster is just asking for a deer in your lap. I live in the Georgia Piedmont, so some hills and no extremely low temperatures.

As others have mentioned, you can potentially increase your efficiency somewhat with the following:

1. follow a semi truck (reduce drag)
2. increasing your tire pressure (reduce rolling resistance)
3. folding in your mirrors (reduce drag)
4. reduce speed to 65 mph (reduce drag)
5. drive when its warmer (reduce battery losses)

Some of the above are probably not safe, or even legal (the mirrors).
My road trips include:

1. Atlanta area to Callaway Gardens near Columbus
2. Atl area to Savannah
3. Atl area to Rome GA multiple times
4. Atl area to Tampa FL
5. Atl area to Great Wolf Lodge (Lagrange GA)

If I get less than 1.9 m/kW I'm disappointed. If I get higher than 2.0 m/kW I'm happy. As others have mentioned, we are basically pushing a brick through the air, so only so much can be expected. YMMV, but your experience seems below the norm.

 

[Dukhudo]

Thanks for the comments. I haven't had a chance to test anything out yet but will be able to take a decent drive this weekend and will record some info.

I would be happy with 1.9-2.0 miles/kWh, but I'm not even getting that with a tailwind.

If what I have is all I can do, I'll adapt as needed.

 

[Dukhudo]

Just took a drive.

10km one way, 10km back.
Flat surface.
5-10km cross wind
No interior heating
No battery heating (according to Car Scanner)
Battery temp was around 14-16 degrees Celcius
10 degrees Celcius
Tire Pressure 39psi at the end of the drive.

Reset Trip when I reached 110 kph and let it stabilize for 5 seconds

Trip showed 35kWh/100km each way going 110 kph with 100% driving for energy use on both.

So after the conversion, 1.8 mi/kWh at 68 mph seems like the best I'm going to get.

Guess this is just how my truck is. Was really hoping there was something I was doing wrong, but doesn't look like it and I'm not sure what else I can check/change.

 

[VAF84]

Just took a drive.

10km one way, 10km back.
Flat surface.
5-10km cross wind
No interior heating
No battery heating (according to Car Scanner)
Battery temp was around 14-16 degrees Celcius
10 degrees Celcius
Tire Pressure 39psi at the end of the drive.

Reset Trip when I reached 110 kph and let it stabilize for 5 seconds

Trip showed 35kWh/100km each way going 110 kph with 100% driving for energy use on both.

So after the conversion, 1.8 mi/kWh at 68 mph seems like the best I'm going to get.

Guess this is just how my truck is. Was really hoping there was something I was doing wrong, but doesn't look like it and I'm not sure what else I can check/change.

Sounds pretty normal to me. If I understood you correctly the outside temp was 50F? If so, that’s actually better than what I get at those lower temps. 1.8-1.9 is what I get above 72F.

 

[Grease Lightning]

So after the conversion,

Sadly I think you may have bought an American Lightning that doesn’t like to be Canadian.

 

[snowy_91]

I have found the lightning does not like crosswinds disrupting air flow over the truck.

Sponsored