Trading 6.7 for 7.3
 

As the title states, I’m considering trading in my 6.7 for the 7.3 gas. My job has changed and I don’t have the need for the diesel any more. Heaviest I will be pulling is a TT a couple times a year that is under 8500 lbs and my boat every weekend which is ~6000 lbs.

It has taken me a while to convince myself to get rid of the diesel. Last 4 trucks have been diesel. 3 Cummins and the current Ford.

I’ve had some crazy trade offers on my truck so I think I would be dumb not to take advantage of the truck market. So for anyone who has swapped from the 6.7 (or any diesel for that matter) to the new 7.3, are you happy you made the switch? I like the idea of cheaper fuel, cheaper servicing, and not having the emissions. Plus, I’ll be able to trade with zero money out of pocket.

Only other thing I can’t decide on is gearing. I’m sure I would be fine with 3.55 but there’s so many people on here saying go with the 4.30. 90% of my miles are unloaded. The other option is go with the 350 and it can have 3.73. The 350 adds $800 (using Ford’s online 2021 pricing). I have a 350 now so ride doesn’t bother me.

You're in the zone where no matter what you get, you'll be fine. As far as the gear, it's not about affecting your pulling potential or ease. You are nowhere near where that would matter. But the taller 3.55 will turn you fewer RPM on the highway unloaded. And lower RPM means less Noise, Vibration, and Harshness (NVH). The slower the engine is turning, the slower the transmission is turning, the slower the driveshaft is turning. The drivetrain makes NVH, so the fewer RPM, the lower the NVH. Forget the fuel economy argument. That is an economic dead end. The difference is within the statistical margin of error.

I pull a 6K TT. Went from a 2500 D-Max to a 1500 6.2. Only thing I wish I had was a bigger fuel tank.

I traded a low mile f-250 16 6.7 that we used to pull a 28ft bunkhouse with on a new f-350 20 (7.3) about 6 weeks ago. Was hard to turn down selling for $500 less than I paid 4.5 years prior. Very happy with the switch. You’ll notice the difference in power some, however the 7.3 has plenty unless towing really heavy.

test drove 7.3s with the 3.55 (an f-250) 3.73 and 4.30 (tremor). Ended up with the 3.73 and think it’s a nice compromise between the other two options.

I went from a diesel to the 7.3 Tremor and have zero regrets. It's simpler and I do not miss the headaches of fuel filters, DEF fluid or emissions issues that I had with my last two oil burners. Plenty of power for what I need.

Titus
I can't comment on the diesel to gas piece of it, but I have been towing similar weights to what you are stating with the 7.3L/3.55. I have had it in some steep grades at high altitudes in the Rockies and it did great. I currently have a 2022 F-350 on order with 7.3L/3.73, I am only doing this for additional payload not towing concerns. One thing to keep in mind when you pick your gearing is if you plan to up-size your tires because that will have a significant impact on the towing capability. The 3.55's and the 3.73's will do well for your stated purpose but I am not so sure if you put 35"+ tires on them. Many (not all) of the folks on here that swear by the 4.30's either have a Tremor with factory 35" tires or aftermarket over-sized tires that impacts final gearing. Before I get flamed, I have nothing against the 4.30's because I understand their value, but the OP clearly stated he is topped out at 8500#'s and is 90% unloaded. Hope this helps.

The way i saw it was picture myself in 5 years. Do I have the money to take the diesel in for repairs and maintenance? Then I opened up the Engine bay of a 7.3 and asked myself the question of "Can you repair almost anything in this engine bay yourself"? The answer was hell yes. Need to change water pump? boom easy access, need to change spark plugs, coils? boom its all right there. Need to fix belts, A/C compressor, alternators, etc. boom its all there. I then looked at the 6.7 engine bay and I dont even see how I could fit a WRENCH in there.

So, 7.3 with 4.30 it is. ALl my towing is under 10k. so no worries.

3.73 gears is a good all around compromise but I'm biased for 3.73 and an F350 would be needed.

Thank you for the info! On the tire size, I meant to add that in my first post but forgot. I would probably go to a 35”/295 tire. I played with a gearing calculator online and using the factory tire size on 18” wheel with a 3.55 and changing to a 35”/20” changed final drive to 3.30ish. Doing same thing with the 4.30s put it at a 4.06 I believe. Also, I am in Indiana so no mountains around me, with the possibility of a sled trip to WY once a year. Im thinking the 3.55 would be fine, even with a 35” tire.

65-70mph mines getting 15 +/- mpg equal to the 6.2 previous. Power.. you must not have driven one, the 7.3 can hold it's own. Changed the oil already and with 8,800 miles still quiet like the day it was purchased. After 200,000 miles most trucks don't retain great value unless you find the right ass for the seat.

If that's your plan, get the F-350 with 3.73's and then with your tires it should put you back in the 3.50 range(ballpark).

I've driven 3 tremors with the 35" duratracs and one 3.55 f250 with 35x12.50 ridge grapplers. Tremor is exactly at 2000rpm at 75mph. The 3.55 truck was closer to 1600rpm if memory serves. I enjoyed the pep of the 4.30 truck far more. I'd say if your coming from a diesel and putting 35" tires on get 3.73 minimum but I vote 4.30, might feel like a dog compared to a diesel with luggy gearing. I have 3.73 6.2 f250 and I'm not getting one without 4.30's for my next truck. 4.30's are probably not nessesary but I think they feel really good paired to the 7.3.

Not that this matters to a truck person, but look at the 0-60 times below:

1967 mustang gt/a 390 7.3 seconds.
1969 ferrari dino 246 7.4 seconds.
1966 Lamborghini 400 GT0-60 7.5 seconds.

I can continue, but you get the point that a f350 7.3 with 4.30's at 8600 pounds runs a 7.3 second 0-60. Acceleration with a trailer up a hill, acceleration pulling into traffic or just blowing off steam.... 4.30's make it pure fun!

The only trouble is; there is nothing to buy. And buying back in the same high market nets nothing.

If you are already talking about bigger tires and coming from a diesel, get the 4.30s, really not much downside... with three overdrives on the 10 speed you are at 2k rpm at 75mph and have little to no noise, smooth as butter. People hear 4.30s and think its going to be screaming on the highway like an old 4 speed, its not, not at all.