Why do american trucks get much better mpg that the lr4?

[ktm525]

LOL yes velocity contribution to drag is squared.

 

[16FujiDisco]

I think it’s several factors that all come into play.

For my own comparison I have a ‘99 Silverado Z71 5.3l na V8 w/ 4spd trans; it gets about 14mpg hwy with no load other than 2 passengers in 2 wheel high. In my ‘16 LR4 with stage III tune/pulleys I get between 17.5-18.5 mpg with 2 passengers plus luggage/coolers for vacations and usually running about 80mph.

Modern trucks have 8-10 spd transmissions, switchable 4x4 vs full time, plus advances in engine technology (ie. cylinder shut off, turbo V6s not SC powered). I’m sure rear end gearing is also a factor

 

[Nechaken]

Took a lil trip from Las Vegas to Lake Havasu the other day. Vehicle computer stated 19.4 average. Manual calculation was 18.2 average. The difference between 70-75 mph and 80+ was noticeable on the computer gauge. Driving the 2015 LR4 without wheel/tire mods.

Jeff

Trust me, it gets worse at 90.

 

[Al Pizzica]

Here in the NE the winter blend is also dragging down fuel mileage. Just did 500 miles at 80 and only got 17mpg. In the summer it would be 18.5.
Yes, these things eat a lot more gas with each mph over 65, I've noticed, don't need Bernoulli for that!

 

[djkaosone]

I dislike all of you with great mpgs. I average 10-12 mpgs and close to 13 on a good day on pavement going 70-80 mph mostly highway speeds. I also average 7-10 mpg on dirt. I would LOVE anything over 15 mpg at this point.

 

[powershift]

I'm back in the city now and my mpg dropped to 12 MPG. Totally acceptable for me, although gas here is a $1 more per gallon at $3.60 for 87 octane. I have yet to buy premium gas.

 

[Nechaken]

Here in the NE the winter blend is also dragging down fuel mileage. Just did 500 miles at 80 and only got 17mpg. In the summer it would be 18.5.
Yes, these things eat a lot more gas with each mph over 65, I've noticed, don't need Bernoulli for that!

I think there's something about the warm up cycle in winter that will **** your mileage as well...

 

[ktm525]

I'm back in the city now and my mpg dropped to 12 MPG. Totally acceptable for me, although gas here is a $1 more per gallon at $3.60 for 87 octane. I have yet to buy premium gas.

Woah. I figured as someone who rags on their engine and just did a rebuild you would feed it premium. Engine must continually be pulling it's spark back?

 

[powershift]

Woah. I figured as someone who rags on their engine and just did a rebuild you would feed it premium. Engine must continually be pulling it's spark back?

Yeah, I love the go WOT with it and drive it in 3rd and 4th gears on the freeway. I'm at 11.4 MPG now. The ECU might be retarding the timing if its getting knock. I need to get my SDD fixed so I can read the knock sensors, timing advance, etc then I could compare 87 octane data logs with 92 octane to determine if there is a difference. I could also do a dyno run with each fuel, but its $145 per session. Tbh, I'd like to get a dyno graph regardless.

 

[Nechaken]

Yeah, I love the go WOT with it and drive it in 3rd and 4th gears on the freeway. I'm at 11.4 MPG now. The ECU might be retarding the timing if its getting knock. I need to get my SDD fixed so I can read the knock sensors, timing advance, etc then I could compare 87 octane data logs with 92 octane to determine if there is a difference. I could also do a dyno run with each fuel, but its $145 per session. Tbh, I'd like to get a dyno graph regardless.

I'd be curious to see the power loss though the whole drivetrain...