Gear Ratio

I have a question about gear ratio's and how it increases towing cap. Ford ups the the trailer weight by 2k lbs. if you have the 4.30 gears. Could I not make up this difference with more power? The weight of the truck and the brake system are the same, just wondering. Or am I missing something here?

Hi there. I will keep it pretty short, but it has to do with the ease in which the truck can start out under load. The higher the ration, the more weight the engine can pull from a start. The downside is the truck runs out of steam earlier at high speeds. The easiest way to think about it is a 10 speed bike. If you have the bike in the small chain ring in the front and the big one in the back, it is very easy to start off from a dead stop. Think about this as the highest ratio on the bike. If you have it on the big ring in the front and the smallest one in the back, it is very difficult to start pedaling from a stop, but you can go much faster at high speed. If you compare diesels with gas motors, diesels have lower ratios because the engines spin at much lower RPMs. A gas burner will have a higher ratio because they run at a higher RPM. Hopefully this makes some sense.

Thanks for info Dave, I guess the question I have is can I over-come gear ratio with power and increased torque. Does it matter if you have 500 lbs. torque at 1800 rpm or at 3500 rpm, which are random numbers I picked. I know you want all that grunt low (diesel) but shouldn't gas with the same numbers work?

What ratio do you have now...4.10? Lower gearing works as a torque multiplier, you need at least 4.30s for towing the Cyclone. I think your best bet is get a tune from Mike at http://www.5startuning.com/6.2L_V8/index.html he owns and has done wonders on the 6.2 Fords. (the 6.8 V-10s too) All safe tunes.

Most truck are rated by the amount of cooling available and capacity of the drive train. The brakes have usualy nothing to do with it.
The more HP produced has nothing to do with pulling capacity if the heat cannot be decipated.
On standard transmissions it use to be the power the clutch had for take off and the trailer capacity was greatly reduced due to take off capacity.

I had a std Ranger with 3500lbs Trailer capacity and the same automatic had 5600lbs capacity. While pulling the standard was way ahead on heat capacity as I was able to tow the same trailer as the automatic with much less heat.

The same with the 6.5L GM diesel had 8600lbs Trailer capacity with the same equipment as the 8.1L gas with 12000lbs capacity. But from my experience was very well equiped with the 6.5L diesel pulling the 12000 trailer I pulled for 9 years.

Well it would. This is the reason diesels are so much better for pulling. They have a much larger torque curve and in your example, the engine is working half as hard to generate the same torque. With a diesel you get torque much sooner and for much longer, where a gas has to rev much higher to generate the similar amounts of power. If your diesel was running at 3500 rpms, you would be in big trouble. The other comment is spot on with heat, if you are running that much higher, you are going to be throwing off tons of heat which kills power, longevity, etc. Tunes are a great idea, but they will void your warranty so make sure you know what you are getting into when you sign up for those. All tunes are 100% detectable, regardless of what the tuning company will tell you so make sure you know the risks. Bottom line is that the 6.2 is a great motor, but it is going to have to work really hard to pull a giant trailer like that. You are going to get miserable mileage and really pushing that motor over what it is comfortable doing. It can, but I would really drive by the gauges and make sure you take care of it so you don't overheat it. I wouldn't worry about the transmission, it is the new 6R140 transmission. What that means is that it has 6 forward gears, reverse and is designed for 1400 pounds of torque. As I like to say, if you have 6 wheels on the trailer, you really need 6 wheels on the tow vehicle. Also, there is a reason why you can't get the duallies in a gas version anymore because when you are towing that amount of weight, you really should have a diesel as they are much better suited for big towing. Sorry to be long winded, but if you are going to tow something that big with a gas burner, expect to get really poor mileage and know that the truck is going to rev REALLY high and in a lower gear to try and generate the amount of torque needed to pull it. You are going to have to really pay attention to your temperatures on your tranny and engine to avoid something bad. Good luck!

The last post by Dave was right point. I know you bought the CY and a new TV. It's too bad we did not know you then. I expect most seasoned RV'ers would have told you a BIG NO on a gas TV. All you can do now is try it and see how it works out for you. I wish you the best of luck........AND WATCH YOUR GAUGES. You don't want to POOOOOF your TV the 1st time out.

Thanks guys for all the good advice and info to help me understand the mechanics of it all. First time out I plan on going empty and not plan on heading far or for any hills. If I feel like it it not going to make it I will be looking to trade truck. The other reason I went gas is diesel is way expensive up here in Alaska. So much that even with poor mileage it is still cheaper to drive with gas. Not to mention that the 7k difference in vehicle price will buy alot of gas. We don't have the options in buying like other folks have. You have to buy what's on the lot or order it and wait six months.

The best thing that can be done to a gas motor is to open the exhaust with a proper efficient exhaust. Everyone I know including myself towing with a gas engine have experienced exhaust leaks caused by high pressure and excess heat at the exhaust manifolds. On my gas truck the manifolds started to leak on the first trip. The exhaust studs failed on one side.

I have little to no experience with Fords other than a 460 in a class C. Definite exhaust manifold leaks. Prior to our current Duramax, I had an 8.1 chevy gasser. I changed the exhaust system and added an Air Aid intake system. Not a big help for the money. The best mod and maybe in combination with the other two was the addition of a throttle body spacer. I have to say, there was definite, seat of the pants, difference in performance and mileage gain.

6.7powerstroke said:

. . . but if you are going to tow something that big with a gas burner, expect to get really poor mileage and know that the truck is going to rev REALLY high and in a lower gear to try and generate the amount of torque needed to pull it. You are going to have to really pay attention to your temperatures on your tranny and engine to avoid something bad. Good luck!

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Would the same thing be true when towing a lighter (North Trail 26RLSS, max 9k pounds) TT? I know my little F150 4.6 gets up to 4k rpm uphill and was hoping a larger engine wouldn't be so bad. I have been actively trying to buy the F250 supercrew gasser with a 6.2 L engine, but now I'm thinking I might get better gas mileage with a diesel (and they are a lot easier to find).

Sounds great Ray, there is not alot of mods out yet for the 20011's. I know on my 03 6.0 the cortex tuner made a huge difference. So right now I am looking at a tuner and exhuast mods. I had my 6.0 in the shop many times after the tuner and not once did I get asked questions. Throttle body spacers work very well, have friends that have put them on. Not sure on warranty issues there?

Fuel millage with a Diesel will be better towing and you can relax more. However if you don't tow a lot then you are paying for something that may be higher than necessary.

pegmikef said:

Would the same thing be true when towing a lighter (North Trail 26RLSS, max 9k pounds) TT? I know my little F150 4.6 gets up to 4k rpm uphill and was hoping a larger engine wouldn't be so bad. I have been actively trying to buy the F250 supercrew gasser with a 6.2 L engine, but now I'm thinking I might get better gas mileage with a diesel (and they are a lot easier to find).

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Well, yes and no. In theory, if the engine puts out more power, it will not have to downshift to maintain power and torque to move the load up a hill. The 6.2L has a ton more power than the 4.6, but depending on where you tow, it still might have to shift down quite a bit. I had a 5.4L in an Expedition and I used to pull a 28' travel trailer. All I could muster over Eisenhower Pass in Colorado was 30 mph, with the gas pedal buried. Now, same pass with my 6.7 and my 12K 5er, I was doing 52 mph over the pass. This is one of the most extreme interstate passes in the US, but you get the idea. A 9K trailer is a good amount of weight, but that 6.2L has a ton of power so you will more than likely be fine.

Now, for the diesel comparison. If you haven't driven a diesel compared to a gas, don't or you will bring it home. The diesel is more expensive up front, but it will also bring a ton more resale down the road. I drive mine as a daily driver and love it. Diesels are more expensive to maintain, but they really have a ton more power. The ratings don't lie.

6.2L - 385 HP at 5500 RPM and 405 lbs of torque at 4500 RPM
6.7L Diesel - 400 HP at 2800 RPM and 800 lbs torque at 1600 RPM

You are going to get roughly twice as much torque at almost 1/3 the RPM, so you can see the difference is pretty wide. That being said, the 6.2L is about 8K less and will pull that trailer no problem. However, when you go to sell it, you will get most of that 8K back in resale. Personally, I love having a diesel as a daily driver and couldn't go back to a gas burner, but that is just me.

I hear ya Dave, and I use to have a 03 F-350 with the 6.0 and it would tow more than you wanted. Another factor for us up here is winter temps. Try starting your truck at -30 below. If it does start you are not going to like the noise it makes, been there! Yes we use block heaters, running a gas gen-set overnight gets expensive. I have also let my truck run overnight because I was scared to shut off. Remember that you have to use high idle, which burns fuel really fast, been there! Sorry don't mean to rant or get down on diesel, because I would own another one.

Thanks folks for the info and especially for the concise explanations of the functional differences between the gasser and diesel platforms. I have been trying to buy a 6.2L F250 for five months and they would never quite meet my requirements (price, options, etc.). Reading this forum (and others) was just enough to put me over the edge so I bought the F250 6.7L last night that I had looked at off and on, but it never quite met my price. Yesterday (probably because it was the last day of the month and it was Ford's "truck month") they finally came around and actually beat the price I had in mind. We live in San Angelo, Texas and only venture north to get out of the heat so the cold is not an issue. I look at the price as an investment, but I was becoming concerned with operating (fuel) costs. If I gain just three mpg (from 8 to 11) I'll pick up about 30 miles for every 10 gallons (or a little over 3 gallons of gas less). Anyway, thanks again all for the info.

Well done. I did buy a diesel with much less equipment for a cheap price. Now I have more equipment in my 2005 then the new fully equiped 2005 those days.

pegmikef said:

Thanks folks for the info and especially for the concise explanations of the functional differences between the gasser and diesel platforms. I have been trying to buy a 6.2L F250 for five months and they would never quite meet my requirements (price, options, etc.). Reading this forum (and others) was just enough to put me over the edge so I bought the F250 6.7L last night that I had looked at off and on, but it never quite met my price. Yesterday (probably because it was the last day of the month and it was Ford's "truck month") they finally came around and actually beat the price I had in mind. We live in San Angelo, Texas and only venture north to get out of the heat so the cold is not an issue. I look at the price as an investment, but I was becoming concerned with operating (fuel) costs. If I gain just three mpg (from 8 to 11) I'll pick up about 30 miles for every 10 gallons (or a little over 3 gallons of gas less). Anyway, thanks again all for the info.

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Excellent decision, you are going to love it. I have had mine close to a year and it still puts a smile on my face when I drive it. Enjoy!

Great Decision as well, you will be impressed with the fuel mileage both during the break in and especially afterwords.

Good luck.

lwmcguir said:

Great Decision as well, you will be impressed with the fuel mileage both during the break in and especially afterwords.

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What's considered a reasonable break in period of these diesels? The book says varied speed and no towing for first 500 miles and then max of 70 mph (yeah, like I would with 65 mph rated trailer tires) for the next 500 miles. I have always thought of a real break in period of 10k miles. Thanks