They do. You guys just want to move the goal posts by saying "well, the 3.73 truck can just downshift". Yeah, so can the 4.30 truck.

 

Tire size simulates different gearing as well. If the standard across all gear ratios was running a 35 inch tall tire then 3.73 with 35 equals 3.73

3.55 with a 33 inch tall tire simulates 3.77
3.73 with a 33 inch tall tire would simulate 3.96

Some superdutys come with 31.5 tall tire some with 34.2 tall tire.

So tire height also is a variable to consider. Most dont care for the 245/75-17 at 31.5 tall.

 

Genuine question here, you spec your truck based on empty towing/hauling?

 

They don't, and it isn't moving the goalposts to set up both trucks at the same MPH at the same RPM and then ask what is the torque at the tire.

This is 60mph, how many times do you think you can downshift? If you have a gasser the most you can downshift with 4.30's is to 4th gear doing 60mph at 5,000 RPM. The 3.73 can follow you on downshifts and will be 60mph in 3rd gear at 5,000 RPM making the same torque to the tire.

 

Even after many many pages of posts I still don't see the big deal of letting the truck down shift to pull the max load the trucks rated for? The 3.73 will pull the load but at higher rpm lower gear " roughly" same rpm that's needed, then up shift to the appropriate cruising rpm. Down fall is it will drink more fuel during these tasks. That's life owning a truck.

Edit made for different wording.

 

That's kind of the crux of the discussion though. The 3.73 will be at a higher rpm than what? If you mean higher than the 4.30, it won't. They'll be at the same RPM, the 3.73 will just be down a gear on the transmission.

If you mean the 3.73, or 4.30, or any other gear ratio will be at a higher rpm while needing it, absolutely. It all depends on how much you're asking for with the right foot.

 

BOTH! Loaded and unloaded because I was already doing these trips with a much lesser of a rig with larger than stock tires and the same rear ratio as what I spec on the f250

half the time its loaded and half the time its empty. And the 3.55 is perfectly capable of towing what its rated for and more, so it was a no brainier for me to be satisfied in either condition. Now absolutely the 4.30 will do more "work" but this 3.55 fits into my realm of things perfectly. This is where I have a hard time with it MUST be a 4.30 or go home attitude. I'd be upset if for my deadhead with the open trailer for 970 miles the RPM levels much higher than need be.

 

Like I've said many times, you can graph things all you want, but they do not apply to the real world. No one, but maybe the top 1%, is going to hit 5,000rpm while towing. Heck, the truck won't let you. I tow 12k in the Appalachian mountains and I don't think I've ever gone over 3500. TFL towed 16k up the Ike gauntlet at 4200rpm. (pic below)

Moving the goal posts. You conveniently picked a <1% scenario that would benefit your argument by using redline to limit results. And because you are artificially limiting RPM's to redline, means you just lost the argument. Why do we have to downshift all the way to redline? (hint: because it's the only way your graph works to suggest 3.73's are 'better').

 

I don't think anyone (certainly not me) is suggesting that it's 4.30 or nothing. If one does a fair amount of highway travel, or tows lighter loads...absolutely explore the higher gear ratio options. Will 3.55's tow 15k up the Ike? Hell yeah they will. Will 4.30's do it better? Hell yeah they will.
That's all. I (and most others here) are in no way saying that a 3.73 or 3.55 truck cannot tow within their ratings perfectly adequately to their owner's satisfaction.

What many of us 4.30 owners are suggesting, is that the only negative to them is empty highway fuel mileage...which is only 0.5 - 1.5mpg. That's it. Everywhere else, they are a better tool to use. Gears are just something the buyer has to weigh the pro's and con's of for their individual use case.

 

There is a lot of good info here. Next time I buy tires Im actually going shorter lol

When I get my gooseneck and actually take 2 jeeps somewhere I can better report how my 3.55 did.

85 percent of the time Im empty and regularly run at 70-80 mph around here.

 

No, dude. You said "The truck with the 4.30 can downshift too". Yeah, and the 3.73 can downshift *again*. Since you were taking the "I can just downshift too" argument I was following that through to its logical conclusion. You can downshift again and again and the 3.73 can follow you down the gears again and again, but there's a limit to how far you can take that. The limit is where you run out of RPM, and the 3.73 truck sticks with the 4.30 all the way from 10th/9th at 1,700 RPM through to the RPM limit in 5th/4th at 5,000 RPM.

The 5k RPM has nothing to do with it. Redline has nothing to do with it. It's not a <1% scenario and that scenario isn't any different than any other scenario. You like 3500 RPM, great look at 3500 RPM. Don't even need a different chart. The 4.30 truck is in 6th at 3,571 and the 3.73 truck is in 5th at 3,685, both going 60mph. RPM is within 100, negligible. You prefer to tow at 2,000 RPM, great you can still use the same chart. The 4.30 truck is in 9th at 1,920 and the 3.73 truck is in 8th at 2,062. Again RPM is within 100, negligible. It's the same thing in every scenario at 60mph. Neither has an advantage over the other. Also I've never once said 3.73 is better, not at all. In fact in this very thread I said my general recommendation is for the 4.30. Now at low speeds like 10mph or 20mph where your 4.30 truck might be using gears 1,2, or 3 it's a completely different story where the 4.30 has clear advantage but we're not talking about 20mph, we're talking about cruising at 60 or 70.

Finally, the graphs absolutely apply to the real world. This is physics. If you think there is something else to it, then state what it is. It is something that can be quantified and included then we can include it. That's how physics works. If your position is that there's some un-graphable un-quantifiable dynamic involved then you're arguing that there's magic involved, and that's fine if you want to believe in magic, but obviously I'm not going to bother arguing against that.

 

Redline is 5700rpm and I have pushed 5k rpm towing my 5th wheel up a couple of steep grades. 5k rpm in 4th gear with 3.73s to pull 17k lbs up a 7% grade at 70mph.

 

But redline looks like 6000.

 

enough bickering closed forever