gear ratio.

[muddyriver]

hey all, I'm looking at purchasing a new tow vechicle. I believe I'm going diesel, but wondering what people think a good gear ratio would be for towing 9,000lbs. I see most 3/4 ford have 3:55. I was thinking at least 3:73. what are the thoughts?

[RCMAN46]

"CTD and don't look back"

I thought the meaning was no need to look back as all of the Fords Chevy's will be far in front of you. :B

[muddyriver]

Thanks for the info. I'm looking forward to the step up in truck and to enjoy the trips more. I'm really looking forward to going farther distancing and showing my kids the US.

[goducks10]

larry barnhart wrote:
it doesn't mean anything but their opinion but CTD is a good truck.
chevman

Your right, it means nothing. Just having some fun. Just got back from a 1100 mile week long trip covering all sorts of terrain. I don't care what brand diesel anyone owns. But for those that do towing with one is just plain awesome. We were up and down in the Cascade mtns, towing against 20-40mph head/side winds in eastern Oregon, cruising for hrs on end at 16-1700rpms in 6th gear getting anywhere from 10-12mpg. Diesel fuel at every stop except for maybe one was cheaper than reg. We went from Keizer Or to Sweethome Or, down to Lakeview Or, over to Frenchglen Or and home. Saw some beautifull scenery and had a blast.

To the OP, we also tow a 9000lb 5'er but have 3.73's. It really doesn't matter too much on gearing as the 6sp tranny will compensate for your terrain. If I had to do it again when buying my Ram I would've got the 4.10 gears. That way it would very rarely shift down. With my setup I'm in between 5-6th gears when running 55-65mph. Whatever you decide on, your Ford 6.7 and a 9000lb trailer will be a perfect combo.

[larry_barnhart]

it doesn't mean anything but their opinion but CTD is a good truck.
chevman

[muddyriver]

goducks10 wrote:

#40Fan wrote:
CTD and don't look back.

x2

I'm not sure what that means! Please explain.

[goducks10]

#40Fan wrote:
CTD and don't look back.

x2

[_40Fan]

CTD and don't look back.

[Tystevens]

muddyriver wrote:
hey all, I'm looking at purchasing a new tow vechicle. I believe I'm going diesel, but wondering what people think a good gear ratio would be for towing 9,000lbs. I see most 3/4 ford have 3:55. I was thinking at least 3:73. what are the thoughts?

You need to know more than just the gear ratio. You need the transmission ratios and so forth in order to understand the final drive ratio. It isn't as simple as just knowing the gear ratio anymore.

For example, my 3.42 (6 spd) 2010 Suburban pulls better than my 4.10 (4 spd) '05 Suburban did. It is because the ratios in the 6 spd tranny produce final drive ratio that are more useful for towing.

[lawnspecialties]

If you're getting a new Ford with the 6.7L, I don't think it would matter. The new 6-speed and the ridiculous amount of power compensates for any gear ratio out there. 9,000 lbs. is nothing to worry about.

My toy hauler weighs over 18,000 lbs. loaded and I have a 4.30. Biggest waste of gear ratio out there for this truck. I wish I had the 3.73 even with that big of a load.

[4x4ord]

You don't have much choice with Ford and no choice with GM diesels. So with Ford if you are wanting to size your truck for a large, over 16000 lb, rv get an F350 dually and it will have 3.73 gears. All Duramax pickups have 3.73 gears. If you want a Ford SRW your choice is 3.31 or 3.55. Often the 3.55 equipped truck will have the 20" tires which are not available on the 3.31 equipped trucks. With the larger tires and lower speed ratio the end result is that your engine rpm is fairly close one to other anyway. Even so the 3.31 gears on the Ford provide a little better mpg than what you will get with 3.55 gears. Not pertaining specifically to your question but if you are buying a Ford srw diesel to tow a fiver avoid the f250, it has very little payload.

[APT]

With 800-ish lb-ft of engine torque, you likely won't notice any difference between 3.31. and 3.55, or 3.73. You will probably be stuck with whatever it has based on tire/wheel size for 2011+ Fords. No one has complained about the power of any 2011+ diesel regardless of axle ratio offered. Pick the trim/options/wheels you like and tow happy.

[BeerCan]

3.55 or even 3.31 would be fine. If you ever think you are going to tow real heavy then I would get 3.73. You will save some fuel with the 3.55/3.31

[bmanning]

If you do go diesel, gear ratio is less of an issue; yes, a numerically higher ratio provides more wheel torque, but the primary reason folks love to tow with diesels is they produce their torque at much lower RPM than gasoline engines...so, a diesel doesn't "need" low gears to get into the optimal powerband as a gas motor may.

Also, as powderman said, newer 5-and-6 speed automatics make rear end gearing less of a factor than with the older 4-speeds. Likewise the crazy amount of power these engines produce; with 800+ ft/lb of torque, lower gears just simply aren't as necessary as before.

[powderman426]

My 05 has 4:10 gears which I feel is overkill in most cases when pulling about 10k. I will say on a 9 or 10 percent grade its handy but I don't often see that. Also as I understand the newer trucks have more speeds in the transmission which can change what is needed in the rearend. I feel a 3:73 is a good match.