New Ford F-250/350 gas engine with 13,000 lbs 5th wheel

Is anyone out there currently doing anything close to this. I see the new Fords with a gas engine and 4.30 rears are rated at 15,000 lbs. for 5th wheel towing. I'm considering replacing my 07 Chevy diesel and would love to go back to a gas engine, but not if I have to get out and push to get up the hills.

Back when I bought the trailer the only thing that could handle it was Diesel, buy the looks of the towing charts, things have changed. But, before I make a decision I would like to hear from people that are actually doing it.   

Personally I would keep the diesel. Gasoline powered is going to be lower in MPG's and still lower in HP/TQ category.  I typically see about 24 MPG empty with my diesel and about 13-14 MPG towing with it. As for my small gas powered truck it barely makes 16 MPG empty. With the economy getting tight I would stay for the higher efficiency vehicle. Diesel have longer lifespan compared to gas. Diesel build more torque from low RPM's where gas need to rev near redline to produce the same. I still say keep the diesel.

Cmg = MPG Total for the Day
Tmg = MPG Total for the Tank

2002 Dodge Ram 2500 (Diesel) Modified 381 Horsepower, 831 Foot Pound of Torque
http://i49.tinypic.com/2zox0yw.jpg

1996 Dodge Ram 1500 (Gas) Mopar Performance PCM the rest is stock.
http://i45.tinypic.com/9b98c1.jpg

The biggest gas engine you can now get in the GM pick-ups is the 6.0L V8, so you are giving up a lot of low end torque, even though it is still rated for 360 hp @5400 rpms. Ford is similar with a 6.2L V8 that produces 385 hp but not until you wind it up to 5500 rpms. It's a more sedate 316 hp @ 4200.

Diesel. 

I don't know what qualifies as "hills" where you live, but out here, hills means 4000' to 9000' in 16 miles.  The only reason I have a gasser is that I got a screaming deal on an old low mile truck that still has a ton of life left in it.  If it was near worn out, I'd be looking at an oil burner.  Even with 460 cubes, it's starting to wheeze at 9600'.  And that's with a 7700 lb TT.  If I were in your shoes, it wouldn't even be a question.

bross said:

Is anyone out there currently doing anything close to this. I see the new Fords with a gas engine and 4.30 rears are rated at 15,000 lbs. for 5th wheel towing. I'm considering replacing my 07 Chevy diesel and would love to go back to a gas engine, but not if I have to get out and push to get up the hills.

Back when I bought the trailer the only thing that could handle it was Diesel, buy the looks of the towing charts, things have changed. But, before I make a decision I would like to hear from people that are actually doing it. 

Click to expand...

There are a few on the FTE forum that are pulling 13K with the new 6.2 with the 4.30 gears and are very happy with it. The new 6 speed transmission with double overdrives makes a big difference when mated to a smaller gas motor. I was thinking of getting one to pull our 16K 5ver but our old 2000 V10 310 hp is still to good a truck to retire it at this time,  there's a lot of miles left in the old gasser. ;D

Denny 

Idaho grows them big for grades... 

http://i53.tinypic.com/ne9jq9.jpg

Like my truck I'm pulling my max torque at ~2,000 RPMs at 831 foot pounds of torque.

There's one stretch between Cloudcroft and Timberon that's about half a mile or so....where my F250 is in low gear, pedal floored, and pulling it at 25 mph at about 4000 rpm.  We're at about 9600' up there, and it's steep.  Fortunately, it levels out a bit after that.

A diesel would be very nice.  The gasser is affectionately called the "Gasper" there. 

Of course, I could dig into the motor and fix that too.  The old 460's left a lot on the table for an old hot rodder like me to mess with. 

Thanks Denny, I found a lot of useful information over there. It looks like most guys are happy with that setup.  I haven't completely made up my mind yet, but I'm leaning that way.

Frizlefrak said:

There's one stretch between Cloudcroft and Timberon that's about half a mile or so....where my F250 is in low gear, pedal floored, and pulling it at 25 mph at about 4000 rpm.  We're at about 9600' up there, and it's steep.  Fortunately, it levels out a bit after that.

A diesel would be very nice.  The gasser is affectionately called the "Gasper" there. 

Of course, I could dig into the motor and fix that too.  The old 460's left a lot on the table for an old hot rodder like me to mess with. 

Click to expand...

I was a big 460 fan for many years and I did build one for pulling and put it in a 81 F250 it was bored 30 over, RV long duration cam,  Edelbrock manifold & carburetor and it would pull down a house at low altitudes but up in the mountains well not so good. I also bought a 91 F250 with EFI 460 and it was a dog until I but a Banks Power pack on it and then it would also pull down a house at low altitudes but in the mountains it was better than the 81 but still not all that great. The V10 with it's over head cams (just like the new 6.2) would run circles around a 460 in the lower altitudes and the mountains and get it done with a lot less fuel.

Denny   

Don't forget that ability to pull is more about torque than horsepower!  Go for the diesel every time (why do you think semi's are all diesels)!

Limey said:

Don't forget that ability to pull is more about torque than horsepower!  Go for the diesel every time (why do you think semi's are all diesels)!

Click to expand...

Pulling is more about gearing than horsepower or torque be it gas or diesel, gearing is why semi's can pull what they do.

Denny

rvpuller said:

I was a big 460 fan for many years and I did build one for pulling and put it in a 81 F250 it was bored 30 over, RV long duration cam,  Edelbrock manifold & carburetor and it would pull down a house at low altitudes but up in the mountains well not so good. I also bought a 91 F250 with EFI 460 and it was a dog until I but a Banks Power pack on it and then it would also pull down a house at low altitudes but in the mountains it was better than the 81 but still not all that great. The V10 with it's over head cams (just like the new 6.2) would run circles around a 460 in the lower altitudes and the mountains and get it done with a lot less fuel.

Denny 

Click to expand...

Yep...exactly.  Mine is an 89 EFI.  Stump puller in the lowlands, but wheezy in the high country.  But the truck has 49K original miles and still looks and runs like new.  Won't be replacing it anytime soon. 

rvpuller said:

Pulling is more about gearing than horsepower or torque be it gas or diesel, gearing is why semi's can pull what they do.

Denny

Click to expand...

Not exactly - the gearing acts as a torque multiplier.  Yes, you can gear a low torque gasoline engine to pull almost anything - but the more you want it to pull, the lower the top speed will be, and the more the engine will rev.  Diesel engines deliver their max torque at the low end of their rev range, and typically hold that torque to the upper end of the range.  Gasoline engines only develop max torque at the top of their rev range.

Limey said:

Not exactly - the gearing acts as a torque multiplier.  Yes, you can gear a low torque gasoline engine to pull almost anything - but the more you want it to pull, the lower the top speed will be, and the more the engine will rev.  Diesel engines deliver their max torque at the low end of their rev range, and typically hold that torque to the upper end of the range.  Gasoline engines only develop max torque at the top of their rev range.

Click to expand...

Not all gas motors develop all the toque at there max rpm, the V10 we have has 80% at I think around 2200 rpms and max torque at 3250 and max HP at 4250.  Diesels run at lower rpms and can't rev for long periods of time so you put higher gears in but a gas motor is made to run at higher rpms so you have to run lower gears. The newer generation of gas motors are made to run at high rpms (at least Fords are) all day long without any negative affects so you can't gear them like a diesel that run at lower rpms. Our V10 runs 2300 at 62MPH in OD and 2900 to 3000 in 3rd with 4.30 gears and 215/85/16 tires and if we are in the mountains I will downshift and hold it at 3600 to 4000 rpms for as long as it takes, with the gearing we have we are always in or close to the max torque ran of the motor like it should be, it's like pulling teeth to get a dealer to put the right gears in a gas truck they all want to gear them like a diesel. After 12 years 121K miles with 90% of that towing heavy trailers the motor runs as good as it did at 46 miles when we picked it up from the dealer, I would love to have a V10 with the new Ford 6 speed instead of our 4 speed, more gears to play with  ;D

Denny   

Denny is absolutely right - a modern gas engine is quite comfortable running at the rpms needed to produce higher torque and hp. The only downsides are (1) noise and (2) greater internal wear.  The latter is not a real concern for an RVer - the gas engine will easily run 150-200k miles before internal wear becomes a noticeable factor. A diesel will go twice that, but so what? Both gas & diesel engines will suffer failures in their radiators, alternators, starters, fuel pumps, etc. with about the same frequency,so neither gives a trouble free experience.

I've never driven one of the new gassers with the new generation 6 speed transmissions.  I'll bet its a tremendous upgrade over the old AOD transmissions my older rigs had.  My wife has a Chevy Malibu with a 6 speed tranny and I've been amazed at how well it performs with a 4cyl engine.  After driving older rental cars with the old 4 bangers and automatics, I'd always said I wouldn't own a 4 cyl with an automatic but this one made me a believer.

What Ford did with their 6 speed is eliminate  the 1 to 1 gear so when you are in 4th (1.15 to 1) with a 4.30 rear end it's about the same as having 4.56 gears in a truck with 1 to 1 drive gear before OD, then they have two overdrives one .86 and the other is .67. the highest .67 would be a good gear for running empty and the .86 would be good for cruising pulling a trailer. They ended up with a good spacing between all the gears to keep the motor in the power band unlike my 4r100 4 speed. The transmission is the biggest reason why the new 6.2 is rated to pull more than my 2000 V10.

I was really thinking about getting a 6.2 so I did a lot of research but in the end my old V10 still has a lot of mile left in it and the return on our investments are going to have to get a little better before we buy another truck. :-\

Denny 

Just my 2 cents worth.  I really admire the new 6.2L in the Ford.  And properly equipped, it is rated to pull something as big as you're mentioning.  However, I really think with something that big, you would be better off with the diesel.  Especially if you are going mountain climbing, or if you are pulling it a lot.  The new 6.7L diesel in the F-250 is sooo much better than the older 6.4L and 6.0, it is as close as you can come to a night and day difference.  If you are not pulling the mountains or going too often or too far, the 6.2L may be what you want.  But I really think you would do better with the diesel.

Just for in case anyone is worried about pulling in the mountains with a properly geared gas motor this is a couple of photos I took a few years ago when we where heading to out favorite boondocking spot in the Colorado mountains. After resizeing the photos they are hard to read but the sign reads 11307 ft. We live in our trailer most of the year and travel all over the US and Canada without any problems, our trailer weights 16K and the we gross around 24K depending on water and fuel on board.

Denny
 

What kind of mileage are you guys seeing between a gasser and diesel?

Obviously not comparing apples to apples, my old '71 F250 with the 390 got 6mph towing our 5er on a good day. The 2000 F-350 dually diesel we have now runs rings around it and easily gets 12.5mpg towing the same load. A camping buddy has a 2000 F-250 with the V10 and runs out of power way before my diesel and gets 7mpg doing it. For towing duties, I just don't see any comparison between gas and diesel engines, other than maybe the price (but buying used pretty much eliminates that).

The old F250 got us into RV'ing and through two seasons before we upgraded. I don't fault it at all. It's just not in the same league as the diesel trucks.