How reliable is the 7.3 really?

S2kstephen · 2026-09-29T08:52:29-0500

We are making some big life changes and one of the things we'll be doing is spending a lot more time traveling long distances on the highway (rarely pulling). That said, we're going to be spending a majority time in states with additional taxes on fuel, so I had the crazy idea of swapping out my 6.7 for a 21+ F150 3.5 Ecoboost or a 17+ F250 7.3 (King Ranch time ideally).

I've read about the 7.3 lifters, the 10spd being finicky or needing rebuilds, and a few other lesser concerns. I will likely swap over a bunch of my modifications from my current 6.7 (starlink, console fridge, lighting, Smartcap, etc).

Would anyone buy a 17+ 7.3 under 75k miles without a Ford warranty? Anything to look for as part of a PPI (or should be verified it was fixed/addressed by Ford)?

Worst case I just cough up the coin for $250 fill ups.

HBTFD · 2026-09-29T10:40:32-0500

If you not pulling much get an f150 with the 5.0.

The Evil Twin · 2026-09-29T10:51:19-0500

Obviously I’m not all up in your finances, but why not keep the sixty-7? It has to get better fuel mileage than a 7.tree with 4.30 gears cruising down the highway. Of course, that depends on the difference between gas and diesel where you are. It’s a hair more than a dollar here.
If you are rarely going to tow anything, and never more than a 150 would do, I would go for that over a 7.3 SD for road tripping. Hands down better comfort and economy.

S2kstephen · 2026-09-29T11:19:16-0500

@HBTFD you suggest the 5.0 over the 3.5 of any gen? I previously had a 13 KR with the 5.0 and it was great. But looking to keep the same creature comforts of the 15+.

We are going from TX to SoCal ($5.50 to $8 for diesel) and traveling between TX/SoCal frequently.

The Evil Twin · 2026-09-29T11:28:41-0500

Another thought is to add a larger fuel tank to your 6.7 and plan fill ups at more reasonable prices.

S2kstephen · 2026-09-29T11:29:38-0500

Funny you mention that - I've gotten a couple quotes for the S&B tank. So that might just be the ticket!

Phillbo · 2026-09-29T11:53:59-0500

The Evil Twin said:
Another thought is to add a larger fuel tank to your 6.7 and plan fill ups at more reasonable prices.

Ive run numbers and the ROI on a 60gal tank does not come from the savings on fuel cost but more the convenience of locations to get gas.... recent trip to Colorado has sealed the deal for me. Ill have one before ever traveling there again. I know why everyone drives Subarus there. The gas stations suck ass for a big rig when towing an RV.

superbooty · 2026-09-29T12:16:54-0500

Internet forums have been the best and also worst thing to happen for vehicles. Issues get overblown by 10,000% because the only people complaining are the ones who have issues. There are hundreds of thousands of 7.3's rolling around, and if they had a serious issue it would be well known (aka the heat treatment issues from the first batch of lifters).

9/10 times on here when there is a post of an engine issue, it is a 2022 or earlier truck, or a commercial truck which are detuned for fuel economy, which leads to less oil pressure at idle and also lifter problems. Both problems have been fixed since 2023. Other than that the 7.3 so far appears to be pretty bulletproof.

HBTFD · 2026-09-29T12:48:35-0500

S2kstephen said:
@HBTFD you suggest the 5.0 over the 3.5 of any gen? I previously had a 13 KR with the 5.0 and it was great. But looking to keep the same creature comforts of the 15+.

We are going from TX to SoCal ($5.50 to $8 for diesel) and traveling between TX/SoCal frequently.

Yes. No turbos, intercoolers, etc. The fuel mileage unloaded is negligible. My kids drive f150s with 5.0s, 147,000 and 238,000 on them. If I didn’t have my 8000lb boat that had the aerodynamics of a parachute I would have a 5.0 F150.

S2kstephen · 2026-09-29T13:08:53-0500

superbooty said:
Internet forums have been the best and also worst thing to happen for vehicles. Issues get overblown by 10,000% because the only people complaining are the ones who have issues. There are hundreds of thousands of 7.3's rolling around, and if they had a serious issue it would be well known (aka the heat treatment issues from the first batch of lifters).

9/10 times on here when there is a post of an engine issue, it is a 2022 or earlier truck, or a commercial truck which are detuned for fuel economy, which leads to less oil pressure at idle and also lifter problems. Both problems have been fixed since 2023. Other than that the 7.3 so far appears to be pretty bulletproof.

I agree, and that was what I was really looking for. Thank you!

The Evil Twin · 2026-09-29T13:27:28-0500

Phillbo said:
Ive run numbers and the ROI on a 60gal tank does not come from the savings on fuel cost but more the convenience of locations to get gas.... recent trip to Colorado has sealed the deal for me. Ill have one before ever traveling there again. I know why everyone drives Subarus there. The gas stations suck ass for a big rig when towing an RV.

True, but if the difference is $3 a gallon (or more in CA) it could add up real fast.
Less so, of course, if you are paying to have it installed.

S2kstephen · 2026-09-29T13:35:49-0500

$5.50/gal is what we have in TX, but spending time out west it ranges from $5.50 to almost $9/gal. So a F150 running ~20mpg with gas could save hundreds each month for the same usage as the 6.7 (which was my daily around the DFW area with the occasional road trip, now it'll be a lot more miles).

ACL · 2026-09-29T14:32:44-0500

I have a 2023 F150 with a 3.5 EB, 2022 F150 with a 5.0 and a 2023 F250 with a 7.3. Have had several 6.7s, do not miss them. I tow everyday, but usually under 10k.

In my experience, all 3 of these combos above are extremely dependable. You will make no bad choice just check its history. And grab one that suits your needs.

I am a V8 big gasser guy. But if I had to choose of my 3 which one for your application it would be our 2023 F150 with 3.5 EB. We get 16.5 MPG with FWC Project M on 35s and loaded for a few days of camping. We used to regularly get 18+ MPG on highway without the FWC.

JoeCO · 2026-09-29T15:09:37-0500

Prior to the F250 7.3 I had a 2015 5.0 and 2023 3.5EB. Both were good and much better gas mileage than the 7.3!!

Texrex11 · 2026-09-29T15:19:38-0500

Delete and chip the diesel. Will stomp any other option.
Dis that to my ‘17 Cummins and I was getting 21 mpg towing, around 25 not towing. Just make sure not to get the rollin coal tunes, that’s for dumbasses who like to consume fuel for no reason.

avocadofarmer · 2026-09-29T15:27:08-0500

The 'hidden' costs of swapping to another vehicle are pretty significant and worth accounting for. Sales tax, registration, insurance, etc, etc. I'm not sure moving from a truck you know getting 17 mpg to a new one getting 20 is going to amount to a hill of beans in light of the associated costs.

S2kstephen · 2026-09-29T15:30:04-0500

ACL said:
I have a 2023 F150 with a 3.5 EB, 2022 F150 with a 5.0 and a 2023 F250 with a 7.3. Have had several 6.7s, do not miss them. I tow everyday, but usually under 10k.

In my experience, all 3 of these combos above are extremely dependable. You will make no bad choice just check its history. And grab one that suits your needs.

I am a V8 big gasser guy. But if I had to choose of my 3 which one for your application it would be our 2023 F150 with 3.5 EB. We get 16.5 MPG with FWC Project M on 35s and loaded for a few days of camping. We used to regularly get 18+ MPG on highway without the FWC.

This is super helpful - thank you! Anything to look for with either 3.5 or 5.0 F150 between 40-60k miles pre-owned other than consistent maintenance?

Riddler6.7 · 2026-09-29T15:30:27-0500

I like the 3.5 H.O. in my wife's Expedition Stealth Performance more than the 5.0 in my F150. I don't think the 5.0 is bad, it just does not feel as good as the 3.5 H.O. We also had a '19 Expedition with the standard 3.5 and it was a great motor and towed awesome too. Noticeable difference with the 3.5 H.O. though. No problems out of any of them. Can't compare any to the 7.3 as I've never driven one.

S2kstephen · 2026-09-29T15:31:15-0500

avocadofarmer said:
The 'hidden' costs of swapping to another vehicle are pretty significant and worth accounting for. Sales tax, registration, insurance, etc, etc. I'm not sure moving from a truck you know getting 17 mpg to a new one getting 20 is going to amount to a hill of beans in light of the associated costs.

Fair point - I'll have minimal sale tax with a trade, registration is minimal here in TX, but likely would have some increase in insurance because it'd be a slightly new truck.