2018 Ford Diesel 3:55 or 4:10 - RV-Dreams Community Forum

Cyride · RV-Dreams Family Member

2018 Ford Diesel 3:55 or 4:10

PIEERE · RV-Dreams Family Member

Of course the 4:10 will need more fuel to operate, but it will definitely be better for low speed heavy pulling especially on initial take off! Are you going to be pulling through mountains, then the 4:10 will be best and won't slow down hauling up steeper passes! Others may say different!

Cyride · RV-Dreams Family Member

Thanks Ed, we live in the Midwest so our local camping will be flat-land towing for short weekend trips. We do plan to travel west in the summer and south in the winter, once at location we will use the truck for commuting for a 2 to 4 month period of time.

Any idea if the mpg drop going to the 4:10 would result in fractional fuel usage or possibly several miles per gallon? I'm very familiar with mountain driving and would not expect or care to maintain higher speed limits going over 2-lane highway mountain passes out west pulling a 5th wheel. Running on I90 or I80 I would like to maintain a reasonable speed.

Jon

Terry and Jo · RV-Dreams Family Member

Jon,

You might not know this, but how are you planning to do your RV'ing? For instance, are you planning to stay in one place for a lengthy time, thus not towing the RV as much as you would be driving around and seeing sights? If you will be doing much more non-towing miles than towing miles, then the 3:55 might be best for you.

I can't speak to any reliable estimate as to the mileage differences between the two differentials as our tow vehicle is a Ford F450 with the 4:88 differential ratio. Our tow vehicle only tows about once a year or so rather than on a regular basis and gets "exercised" about every 3 to 4 weeks.

Terry

Cyride · RV-Dreams Family Member

Terry, we plan to use it here for the next year traveling about 100 miles to the east side of the state for a couple of long weekends and then a half dozen times to camp sites within 20 miles. Next year we are planning a three week trip to the Grand Teton National park. In a couple of years when we are retired we will spend a couple of months out west each summer. We will travel to our location, park the trailer and use the truck and motorcycle to "see the sites" in the area we choose to stay. Once my wife retires (she is a teacher) we will also take a winter trip down south and again drop the trailer and use the truck and motorcycle. We plan to volunteer at the national parks in the summer. In the winter there are a couple of christian camps we would like to volunteer for.

Thans Terry!

Lynn and Ed · RV-Dreams Family Member

Not to get into Ford versus Ram, but you might want to consider the difference between Ford and Ram’s exhaust brakes. We had friends recently upgrade their truck, even though they were long time Ford owners they ended up purchasing a 2018 Ram—after taking out an equivalent 2018 Ford and 2018 Ram and driving them over the same roads. Their test is not scientific (nor where they towing during their test), but they said there was no comparison between the Ford and Ram exhaust brakes. When they turned on the Ford exhaust brake they hardly felt a difference and when they did that same thing in the Ram they clearly knew the engine was helping to slow them down. Their main reason for purchasing a new truck was to better handle downhill towing.

Personally, I would always go for the higher gear ratio. Towing is why you are purchasing the truck. Also, the higher gear ratio provides you with more flexibility, if you choose to purchase a different RV in the future.

Lynn

-- Edited by Lynn and Ed on Saturday 14th of April 2018 09:44:46 AM

RonC · RV-Dreams Family Member

FWIW ... a higher gear ratio will make an exhaust brake work better due to the higher RPM’s as will a bigger turbo. The latest “Fast Lane Truck Ike Gauntlet” (YouTube video) all of the big three had nearly identical down hill performances ... to the point that they chose to give each truck the maximum score in that category. There were differences going up the hill, but not down.

Cyride · RV-Dreams Family Member

Thanks all for your input. I ordered the truck today and went with the 3:55. In my case I think over all it will be the best option for our use. It was great to watch the Gauntlet run! If its any concession the Ford won the TFL drag race!!!! As for the Ford vs Ram choice it was a very hard decision for me. I really liked the air suspension of the Ram. One of the concerns I had with the Ram over the Ford was the limited fuel capacity of the Ram. I did not want to add a second fuel cell to the truck and I was very surprised the Ram only allowed 32 gallons of fuel compared to Fords 48 gallon tank. I believe either truck would have done a wonderful job for me. The decision swayed me to the Ford simply because our local Ford dealer offers a lifetime drive train warranty with the purchase of any new vehicle. Hope the warranty is worth it but it did not cost me anything as they priced the truck lower than any of the other three dealers I tried to order it from. I have a question about the rear end choices of the Ford and will open a new thread to address it.

Take care all and thanks again for all the help!

Jon

RonC · RV-Dreams Family Member

Cyride ... you really can’t go wrong with any of the big three CURRENT models. They have come a long way in the last few years. Congratulations on your new truck!

mds1 · RV-Dreams Family Member

Cyride, congratulations on the new truck. It's a hard decision to make and I'll bet you like having that one out of the way. I hear ya on the fuel tank capacity on the long bed Ford being preferred over the Ram. I also like the Ford's tow mirrors and available blind spot monitors. Huge payload capacity on the F350 dually as well.

I'm still trying to make the decision on the gear ratio. We are also not looking to buy anything over 19,000 gross trailer weight and four of the five trailers we are considering are no more than 16,500 gross. Most of the reading I've been doing suggests the fuel difference between the 3.55 and 4.10 is about a wash for mixed pulling/unloaded. But I'd have to think if someone used the truck for a daily driver with little towing in between, such as vacations and such, the 3.55 would be a plus on fuel consumption.

In the Ford, as you wrote, the 3.55 and 4.10 are rated to pull considerable loads. Have to watch that a little in the Ram configurations. Personally, in the Ford I'd not worry much about buying a truck I wanted off the lot just because the gear ratio is 3.55. I figure the engineers at Ford know a little bit about configurations and there is a reason the stock trucks with certain gear ratios as a standard.

Cyride · RV-Dreams Family Member

Thanks Ron and Mark, it is nice to get the truck purchase out of the way. Now we can put all of our attention on purchasing the 5th wheel. It will be interesting to see if there are many changes in the 2019 model trailers that are soon to hit the dealers! Its really nice to get the truck options that will help with the drive time such as BLIS to help with blind spots and the ultimate tow camera system. And from what I have read I will be able to program the trailer tires into the system to monitor the truck and trailer tire pressures. Good luck on your purchase Ron and thanks again for the help.

Cyride · RV-Dreams Family Member

Meant good luck on your purchase Mark!

Zeek · RV-Dreams Family Member

Hello. I have the 2017 Ford F350 DRW, super crew with the 4.10 with the 17" wheels. My old F250 had 22" wheels and 3.55 rear. Both diesels. I have noticed very little difference in fuel mileage with the 4.10 (about 1-2 MPG) both loaded or unloaded.

Personally, with you not being anywhere near your towing capacity with either truck, I would get the 3.55 to get all the extra MPG you can. With that 6.7, new turbo and aluminum body I doubt you will unhappy with the higher ratio. Get the truck you like the best. I think you will be happy, it is an awesome truck. You will love all the cameras, nice mirrors, tailgate, you name it.