starting to look at trucks

valhalla360 wrote:

Terryallan wrote:


so you are saying. They should only make ONE rear gear ratio? Wonder why they still make lower gears, and rate them to tow so much more? It's a puzzle.

Not sure how you came up with that?

The 10speed means you have a gear ratio available that matches what the rig needs to what the engine produces.

With the old 3 speed transmissions, you often wound up having to drop down to a gear that was too deep, so the engine would be lightly loaded but screaming at high RPM when towing. A deeper rear-end could allow you to run in the higher gear and keep the engine better loaded at lower RPM. (This assumes you are within ratings with either rear-end...no one is suggesting towing beyond the ratings). Of course when not towing, the truck winds up running higher RPM and less efficient. And even with the deeper rear-end, it still didn't always match up well to power needs.

With the 10speed, those issues largely go away. For a given situation, the truck may pick a different gear if the rear-end is changed out but the overall gear ratio will be nearly identical.

Only reason you might need a deeper rear-end is to boost the ultimate towing capability but the discussion presumes he isn't over the tow rating and it is about drive-ability.

I just go by the rating for the different gears. and YES they make a huge difference, Especially up, and down mountains, and starting from a stop. that is one of the reason for the lower gears. Another is keeping the engine in it's power band. Still a puzzle.

If you had ever seen the difference in gear ratios as they run. you would better understand the difference, between a 3.73, and a 3.05. I see it every day. It is what I do.

Based on the Ram forums I frequent, the 8 speed transmission made the axle ratio much less important. I think the various ratios Ford offers with the 10 speed (mated to nearly 400HP) are probably mostly a sales gimmick.

Terryallan wrote:


so you are saying. They should only make ONE rear gear ratio? Wonder why they still make lower gears, and rate them to tow so much more? It's a puzzle.

Not sure how you came up with that?

The 10speed means you have a gear ratio available that matches what the rig needs to what the engine produces.

With the old 3 speed transmissions, you often wound up having to drop down to a gear that was too deep, so the engine would be lightly loaded but screaming at high RPM when towing. A deeper rear-end could allow you to run in the higher gear and keep the engine better loaded at lower RPM. (This assumes you are within ratings with either rear-end...no one is suggesting towing beyond the ratings). Of course when not towing, the truck winds up running higher RPM and less efficient. And even with the deeper rear-end, it still didn't always match up well to power needs.

With the 10speed, those issues largely go away. For a given situation, the truck may pick a different gear if the rear-end is changed out but the overall gear ratio will be nearly identical.

Only reason you might need a deeper rear-end is to boost the ultimate towing capability but the discussion presumes he isn't over the tow rating and it is about drive-ability.

valhalla360 wrote:

Terryallan wrote:

Kind of proved my point. The lower rear gear gets you to the needed RPM for max torque.

As for the other statement about the 10 speed. Ford's engineers determined the tow capacity is always higher with the lower geared rear. No matter how many gears it has. A truck will NEVER be rated for max tow, with a 3.15 rear gear. It's in the book, and is no more than physics.

If it's rated to tow north of 7k lb, the Ford Engineers have determined, it's fine.

This is different from the old days of 3 speed transmissions where there often wasn't a good gear to match engine output, so you really needed the deep rear end if you wanted to tow much of anything otherwise you lived in 1st gear with the engine near redline if you wanted to go more than 35mph. The 10speed allows the truck to pick a gear that matches the engine output, so unless you are pushing over the tow limits, the rear end isn't a big deal.

so you are saying. They should only make ONE rear gear ratio? Wonder why they still make lower gears, and rate them to tow so much more? It's a puzzle.

I just started towing w/my f150 5.0L 10 speed and it is easy to keep the rpm's up w/ the 10 speed. Our truck is also a daily driver at home and of course on the road. My TT gvwr is 6500 and I have no problem towing 55 to 60 MPH on long grades and I keep the RPM's up to 3-4K. The engine runs cool w/ the bigger radiator. I get 10.3 towing and 23 w/ out at 75MPH. Love my 1/2 ton for daily driving and that's why I didn't get a rougher riding 3/4 ton.

MR MAC wrote:
I'm in no hurry, but looking at used (2016 and up) F150's, looking at eng. size and wondering what would be best a 3.5 Ecoboost or a 5.0 L V8 . to pull a 7000lb trailer (TT) I think I"m leaning towards the V8, to pull over hills in Maine.

Thanks Rob

Rob,
Is the trailer you're going to pull 7k empty or 7k loaded ready to hit the road?
If 7k empty I would look for a 3/4 ton...if 7k loaded the F150 would be my choice. The trailer I have is 30ft 7k loaded and its a perfect match for my truck....would I go heavier and bigger with it no I would go 3/4 ton then. I've put over 40000 towing miles on my 2 ecoboosts and they are the best mountain towing gasoline engine you can get IMO. I had an 11 5.0 for 3 months after a couple pulls with that thing I wanted to dump it fast as that Naturally Aspirated engine screamed and sucked the fuel at 8mpg on a great day. The same route with the 3.5 Eco I get 10.5 on a great day and 9.5 on the worst day. In 40k I have yet to tow my 7k trailer and get below 9.5 mpgs with either of my 3.5 Eco's. On 1200 mile trips I avg between 10 and 10.5. Would I ever own a 5.0 V8 again...NEVER...It's either 7500lbs or less with an 3.5 Eco or I'm stepping into the 3/4 or 1 ton with anything over 7500k. Oh and btw my 18 Eco is spec'd to tow 13000lbs too. Payload is your limiting factor with any vehicle.

I love my f150. its a 2016 XLT super crew, 4x4, 5.0 bought new at the start of 2017 for a killer price (I was looking for a newish used it ended up being cheaper) Minimal bells and whistles but lots of what I needed. get the most payload you can it will be your limiting factor. Both the coyote and the 3.5 Eco boost are very capable motors and will do fine. One thing I don't like is my 331 rear end. would rather 355 but I do get great mileage. real world differences are minimal between the 2 motors. the eco gets slightly better mileage and makes a bit more power (under boost)but has more moving parts..... I would buy another of my truck in an instant. As a comparison I bought my wife's explorer a year later and it doesn't meat my f150 at anything. It burns more fuel, costs more to buy and insure, has less room and the 7th seatbelt it comes with is seldom used. The ONLY reason it wasn't another f150 is because the lot where she works makes the truck cumbersome.

Terryallan wrote:

Kind of proved my point. The lower rear gear gets you to the needed RPM for max torque.

As for the other statement about the 10 speed. Ford's engineers determined the tow capacity is always higher with the lower geared rear. No matter how many gears it has. A truck will NEVER be rated for max tow, with a 3.15 rear gear. It's in the book, and is no more than physics.

If it's rated to tow north of 7k lb, the Ford Engineers have determined, it's fine.

This is different from the old days of 3 speed transmissions where there often wasn't a good gear to match engine output, so you really needed the deep rear end if you wanted to tow much of anything otherwise you lived in 1st gear with the engine near redline if you wanted to go more than 35mph. The 10speed allows the truck to pick a gear that matches the engine output, so unless you are pushing over the tow limits, the rear end isn't a big deal.

Well, I have a 2017 F150 3.5 Eco/3.55 rear. I pull a Keystone Passport Ultra Light 153ML, weights no more than 5K lbs. fully loaded. 3.5 Eco gets about 7-8 MPG towing. No better than my SuperDuty dually with 6.2/4.30 combo I sold. What it is good at is empty MPG.

Gman

bartlettj wrote:
I think 8k pounds for a F150 is a bit heavy as you are going to be light on truck payload if you plan to take passengers in the cab. There's not much of a price premium on used 3/4 ton trucks unless you go diesel.

which leads to the question. Is that 7000 loaded, or 7000lb dry? An important thing to know.