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Hey guys, just wanted to share with you guys some of my summer adventures with my 4bt powered ford expedition. Drove from Southern British Columbia to the yukon, around 6500 kms round trip. I did 20 imperial mpgs(16.5-17 us mpg) the whole trip. Scaled truck and trailer at 11500 lbs with a full tank and the family all loaded up. Truck is lifted with 35s. Nv4500. Hx30 over hx35. 4bt ran like a dream the whole way. Added maybe a cup of oil one time. Pulled most hills in 4th, had to grab 3rd maybe half a dozen times tops. Kept egts at 1100, downshifted when it got hot. Only got passed by cars and unloaded pickups. This is driving through the rocky mountains alot of the way, very little flat sections.
What do you all think, am I leaving some milage and power on the table or do I have her set up nice?
 

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Your setup is very much like Eggman's on his F250. If you have 5x.012 injectors like his you're probably getting near 300 HP. What boost level are you seeing. He limits his to around 40 PSI. Your mileage is probably pretty close to his. Running the truck without all the extra load on level ground should get you into the low to mid 20 MPG US range. All that power isn't free, but you'd probably be lucky to get 10 MPG with the load you have with a gas engine. See any wildlife other than the 2 legged human variety?
 

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Hey guys, just wanted to share with you guys some of my summer adventures with my 4bt powered ford expedition. Drove from Southern British Columbia to the yukon, around 6500 kms round trip. I did 20 imperial mpgs(16.5-17 us mpg) the whole trip. Scaled truck and trailer at 11500 lbs with a full tank and the family all loaded up. Truck is lifted with 35s. Nv4500. Hx30 over hx35. 4bt ran like a dream the whole way. Added maybe a cup of oil one time. Pulled most hills in 4th, had to grab 3rd maybe half a dozen times tops. Kept egts at 1100, downshifted when it got hot. Only got passed by cars and unloaded pickups. This is driving through the rocky mountains alot of the way, very little flat sections.
What do you all think, am I leaving some milage and power on the table or do I have her set up nice?
EXCELLENT!
 

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I think you are solidly in the Sweet Spot and do not see how you could expect much more with a mechanical turbo diesel. That was a great real world test drive and now family memory for the book as well one of many I hope.
 

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Discussion Starter · #8 ·
Thanks guys! It's a great trip, highly recommended exploring bc, yukon (one day I'll go back for the alaska portion).
Saw lots of moose, bear, a few carriboo, and thin horn sheep.
My set up is similar to Eggman, I don't see more than 40 psi either. Usually seeing 25-30 on a good pull.
I'm happy with milage. My expedition totally stock struggled to get 10 mpg imperial while pulling 4k(truck weighed 2k less and had 31s vs 35s). So that's a vast improvement!
My 4bt used to be in a lifted ranger so I used to get 30-35 mpg imperial, but that was vastly lighter.
 

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At 25-30 PSI boost you're probably not over 200 HP. You could probably turn it up some more and not affect the fuel mileage very much if any. Diesels are kind of weird. I have seen some mods the increase power and increase fuel mileage at the same time. Doesn't make sense but you're improving the efficiency of the engine. Sounds like you had a great trip.
 

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Discussion Starter · #10 ·
At 25-30 PSI boost you're probably not over 200 HP. You could probably turn it up some more and not affect the fuel mileage very much if any. Diesels are kind of weird. I have seen some mods the increase power and increase fuel mileage at the same time. Doesn't make sense but you're improving the efficiency of the engine. Sounds like you had a great trip.
I can hit 40 psi, just while towing I usually hold 25-30 on the hills
 
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