May be in the market in the future for a new 1/2 ton truck. Currently in an F150 approaching 100K miles and would like to put more focus on fuel efficiency for my next truck.

Does anyone have experience with both or either of these engines?

Considering the GMC Sierra SLT or AT4 with the 3.0 with 6.5' bed or the F150 Lariat Power boost with a 6.5' bed.

I've got a 24 GMC with the 3.0. Got about 20k miles on it and no issues. Good power delivery, averaging a little over 24 mpg. Haven't tried towing anything more than a 10' utility trailer with it yet so can't speak to that aspect really.

I don't think you can go wrong with either. I love my Powerboost. Great power and the fuel economy is nice. Mixed driving, I average about 22 mpg. People I know who have the 3.0L love theirs, too.

Personally, I just think the driving profile of the PB is better than the Duramax.

I had a 2021 F150 with the 3.5 boost. Now I drive a 2023 AT4 with the 3.0 diesel.

I really like them both. The boost feels quicker, but not by a large margin. The new turbo on the 3.0 has great response and was supposedly a big upgrade from the last one.

Got 22 mpg on the boost and get about 24 on the 3.0. The boost is going to have a better towing capacity, especially if you get the max tow package (it would be around 9k vs 13k, if memory serves).

Overall I like the AT4 better. I like the ride, interior and exterior a little more. I will say the seats in the F150 were more comfortable.

I used to make fun of the GMC multifunction tailgate....until I owned one. I love it.

f burg ag said:

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I had a 2021 F150 with the 3.5 boost. Now I drive a 2023 AT4 with the 3.0 diesel.

I really like them both. The boost feels quicker, but not by a large margin. The new turbo on the 3.0 has great response and was supposedly a big upgrade from the last one.

Got 22 mpg on the boost and get about 24 on the 3.0. The boost is going to have a better towing capacity, especially if you get the max tow package (it would be around 9k vs 13k, if memory serves).

Overall I like the AT4 better. I like the ride, interior and exterior a little more. I will say the seats in the F150 were more comfortable.

I used to make fun of the GMC multifunction tailgate....until I owned one. I love it.

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Are those hand calcs or from the truck computer? My follow up question was going to be if the AT4 does better than the 21/23 advertised and if you are hitting 24 then this seems like a no brainer for me.

Just took my 24 AT4 on a road trip to Colorado and back and averaged a little over 23 round trip using the Fuelly app. With that said, we also were going about 85mph the whole way back which killed some of the mileage I was getting. 2 tanks were at 25 and 24.2.

I cannot complain about the truck other than I miss my Tremor, I miss the larger tank, I miss the seats.

Silvy said:

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Kyle Field Shade Chaser said:

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My PB gets garbage gas mileage. I have the 6.5 foot bed. FX4 Lariat. 19.2mpg avg. but I still love it.

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I can get about 18.5-18.9 on my 2019 Expedition MAX in mixed driving around Houston so that seem abysmal.

Yeah it's something to do with the cat. They reprogrammed it twice. It'll get 21.5mpg for about two months and then go back down to 19mpg.
They keep telling me it's "within technical tolerance" after they reprogram, but it goes bad again a few months later. I'll eventually have to replace the cat.

If I cruise my PowerBoost at 60 to 65 mph I can get to 27mpg

I don't do that very often

crazy you guys get that kind of mileage.

I get 17pmg on my 3.5EB. Max tow package, slightly bigger tires (275/70/18). Even with pure stock, I never got above 19. No idea how you guys are getting 20+.

I have a 22 PB with the 7.2kw generator. I only get about 21 mpg no matter what I do living in Houston. When I was running the house off the generator for that last hurricane, it looked like I was burning 18ish gallons for about 24 hours. Tank is only 30 gallons so no way I would even get 48 hours. It looked like I was running about 3kw running AC and all electronics

ChoppinDs40 said:

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crazy you guys get that kind of mileage.

I get 17pmg on my 3.5EB. Max tow package, slightly bigger tires (275/70/18). Even with pure stock, I never got above 19. No idea how you guys are getting 20+.

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Doesn't sound like you have a power boost, just the standard eco boost ?

Correct but people here saying they're getting over 20 with the regular 3.5EB

ChoppinDs40 said:

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Correct but people here saying they're getting over 20 with the regular 3.5EB

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Not sure what to tell you. I had the 3.5EB with max tow and consistently got around 22 mpg. I guess I drive like the old man I am becoming.

Why would I lie about the MPG on a vehicle I don't even own anymore? Another Ag that lurks around here bought it…..maybe he can post his habits and MPG with the same truck.

f burg ag said:

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ChoppinDs40 said:

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Correct but people here saying they're getting over 20 with the regular 3.5EB

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Not sure what to tell you. I had the 3.5EB with max tow and consistently got around 22 mpg. I guess I drive like the old man I am becoming.

Why would I lie about the MPG on a vehicle I don't even own anymore? Another Ag that lurks around here bought it…..maybe he can post his habits and MPG with the same truck.

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Not saying you're lying… more of just, what am I doing wrong? I normally cruise at 75 on highway (often in Eco mode). I don't have a lead foot.

I can't imagine an E rated tire that's 1.5" taller than stock would take that much from my mpg.

Right. So I just ran one A/C unit for the bedrooms, a TV & router, a fridge & small deep freezer. Flipped off everything else. Our power came back on after two days, and I still had about a quarter tank of gas.

ChoppinDs40 said:

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f burg ag said:

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ChoppinDs40 said:

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Correct but people here saying they're getting over 20 with the regular 3.5EB

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Not sure what to tell you. I had the 3.5EB with max tow and consistently got around 22 mpg. I guess I drive like the old man I am becoming.

Why would I lie about the MPG on a vehicle I don't even own anymore? Another Ag that lurks around here bought it…..maybe he can post his habits and MPG with the same truck.

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Not saying you're lying… more of just, what am I doing wrong? I normally cruise at 75 on highway (often in Eco mode). I don't have a lead foot.

I can't imagine an E rated tire that's 1.5" taller than stock would take that much from my mpg.

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Do you have a boost gauge? 3.55 or 3.73 rear gear?

What RPM are you running at 75mph on level ground?

I would imagine anything about ~65mph drops your fuel efficiency immensely, because, well, it's a giant brick truck with big tires that weights 5000lbs.

Flaith said:

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ChoppinDs40 said:

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f burg ag said:

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ChoppinDs40 said:

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Correct but people here saying they're getting over 20 with the regular 3.5EB

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Not sure what to tell you. I had the 3.5EB with max tow and consistently got around 22 mpg. I guess I drive like the old man I am becoming.

Why would I lie about the MPG on a vehicle I don't even own anymore? Another Ag that lurks around here bought it…..maybe he can post his habits and MPG with the same truck.

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Not saying you're lying… more of just, what am I doing wrong? I normally cruise at 75 on highway (often in Eco mode). I don't have a lead foot.

I can't imagine an E rated tire that's 1.5" taller than stock would take that much from my mpg.

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Do you have a boost gauge? 3.55 or 3.73 rear gear?

What RPM are you running at 75mph on level ground?

I would imagine anything about ~65mph drops your fuel efficiency immensely, because, well, it's a giant brick truck with big tires that weights 5000lbs.

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Yes, I run the boost gauge on the screen vs. Oil pressure.

3.55 rear with the 10speed. at 75mph, flat, it's usually around 1.8k rpm in 10th.

However, on the way to the airport this morning, I set the cruise to 70mph and I bet I averaged 20mpg or more.

Where, I'm seeing it drop immensely is going uphill at those speeds (obviously) and that's always driven by the turbos spooling (rpms don't even go up that much). I also read that eco mode may actually not be good if going 75pmh+ because it defers to spinning the turbos vs. upping the rpms.

I understand it's a big truck and won't get awesome mpg but when others are saying they're getting 20+ mpg and all I've done is put on 275/70s vs 275/65s (stock), I struggle with that one change zapping my mpg by 3+.

For reference, it's a 2021 with just over 40k miles, so it shouldn't be a sparkplug or some other issue.

As mentioned above, it's certainly the tires. If the engine RPM increases, there's more exhaust moving out of the engine. When more exhaust is leaving the engine, you're moving more air into the turbos. When the turbos are pumping more air into the engine, the fuel injectors will dump more fuel to maintain proper air-fuel ratio.

If you want to improve your fuel economy, lessen the load on your engine.

did adjust your speedo for the tire change? that's almost a 5% difference in revolutions per mile. so an average of 19.5 mpg would really be over 20 mpg.

Roger350 said:

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It is absolutely the tires. I bet the E rated tires are at least 15 lbs per tire heavier than the P-Metrics it came with. 15 lbs of rotating mass plays hell on gas mileage.

Seeing as they are taller too, the weight difference may be closer to 25 lbs a tire. Then add in the fact that the engine is now working harder because of the loss in gearing from the larger diameter, and I would expect a large hit in fuel economy, 3 mpg would not surprise me at all.

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Just compared weight. OEMs were 49lbs a tire. KO2s are 57lbs.

Furlock Bones said:

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did adjust your speedo for the tire change? that's almost a 5% difference in revolutions per mile. so an average of 19.5 mpg would really be over 20 mpg.

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No, I asked the dealership if they would and they just kind of laughed it off only going up ~1.5"

I considered that. It's more like 3-4%. Radars will show me going 71 when I've got it set at 70

i have a 3.5 ecoboost tremor.18 inch all terrains (stock)

I average about 17-18 commuting overall. but if I'm all highway the sweet spot is about 70-72 mph with 93 octane. i can get 21-22 mpg doing that. hard to want to go that slow on texas highways. i just got back from a roadtrip to the panhandle and average 19 mpg at 75-80mph.

ETA: ford owners manual say 91 octane or better for best performance. that includes towing and the heat. i putter around town with 87 but anytime i leave town i put in 93 and ethanol free where i can. definitely better MPG with the higher octane.

FightinTAC08 said:

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i have a 3.5 ecoboost tremor.18 inch all terrains (stock)

I average about 17-18 commuting overall. but if I'm all highway the sweet spot is about 70-72 mph with 93 octane. i can get 21-22 mpg doing that. hard to want to go that slow on texas highways. i just got back from a roadtrip to the panhandle and average 19 mpg at 75-80mph.

ETA: ford owners manual say 91 octane or better for best performance. that includes towing and the heat. i putter around town with 87 but anytime i leave town i put in 93 and ethanol free where i can. definitely better MPG with the higher octane.

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I did higher octane pulling my TT to Colorado and back last summer. The mpg difference was pretty negligible and not worth it for the increase in price vs MPG. Premium is way higher in those smaller towns on 287/87.

Are you using eco-mode on the highway?

i only use normal mode and i don't do any towing.

the price difference in octane still makes 87 the cheaper option on total $/MPG. i just prefer to run the higher octane when i can.

ChoppinDs40 said:

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Roger350 said:

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It is absolutely the tires. I bet the E rated tires are at least 15 lbs per tire heavier than the P-Metrics it came with. 15 lbs of rotating mass plays hell on gas mileage.

Seeing as they are taller too, the weight difference may be closer to 25 lbs a tire. Then add in the fact that the engine is now working harder because of the loss in gearing from the larger diameter, and I would expect a large hit in fuel economy, 3 mpg would not surprise me at all.

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Just compared weight. OEMs were 49lbs a tire. KO2s are 57lbs.

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Where are you getting the weights and are you looking at SL or XL tires? I just looked around DTC and the heaviest SL/XL in 275/65-18 I found was just under 45 lbs, most were 40-43 lbs. A 275/70-18 E rated KO2 was 58 lbs.

I hear great things about the 3.0 diesel.

Silvy said:

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ChoppinDs40 said:

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Roger350 said:

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It is absolutely the tires. I bet the E rated tires are at least 15 lbs per tire heavier than the P-Metrics it came with. 15 lbs of rotating mass plays hell on gas mileage.

Seeing as they are taller too, the weight difference may be closer to 25 lbs a tire. Then add in the fact that the engine is now working harder because of the loss in gearing from the larger diameter, and I would expect a large hit in fuel economy, 3 mpg would not surprise me at all.

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Just compared weight. OEMs were 49lbs a tire. KO2s are 57lbs.

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Where are you getting the weights and are you looking at SL or XL tires? I just looked around DTC and the heaviest SL/XL in 275/65-18 I found was just under 45 lbs, most were 40-43 lbs. A 275/70-18 E rated KO2 was 58 lbs.

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Tire rack. Looked at the SL rated wrangler duratrac that came on my truck. Yes I know the OEM ones may be different than the ones you would buy afterwards but figured it was close enough a metric to verify.

https://www.tirerack.com/tires/tires.jsp?gclid=CjwKCAjwk8e1BhALEiwAc8MHiP8Ohpq6Kvfk0DB9A1caiOGOsv7s2PKMST861NgXtUHsmekQeTpdZBoCogoQAvD_BwE&tireMake=Goodyear&tireModel=Wrangler+DuraTrac&partnum=765QR8WDTV3&GCID=C13674x012-tire&KEYWORD=tires.jsp_Goodyear_Wrangler+DuraTrac_Tire&code=yes&ef_id=CjwKCAjwk8e1BhALEiwAc8MHiP8Ohpq6Kvfk0DB9A1caiOGOsv7s2PKMST861NgXtUHsmekQeTpdZBoCogoQAvD_BwE:G:s&s_kwcid=AL!3756!3!!!!x!!&gclsrc=aw.ds&gad_source=1&gbraid=0AAAAAD_rH__tYLzyYKPh00_RAol7_SbDX

Haha same!! I get like 14