2006 Explorer 4.6 v8 has no power to tow up mountains?

[jimh406]

I intended to use my 2006 4.6 v8 Explorer to tow my driftboat/trailer with a few tires over the Cascades and Rockies this weekend. I hadn't even made it from Seattle to Snoqualmie Pass before I decided to turn around.

My guess is the driftboat/trailer with tires was still no more than 1500 lbs and probably closer to 1000. Those of you who tow with yours, should I expect high revs to maintain 65-70 going up mountains with this type of load? How many RPMs should I expect up to 6000 ft?

If not, what should I check? My 2006 Limited is AWD with 18 inch wheels. The tires are slightly larger than stock size.

NOTE: I took it to Montana using a F450 instead. Obviously, a bit overkill for a light towing load.

[Sam_Spade]

jimh425 wrote:
Thanks for all of the comments so far. It helps me understand what's going on.

It's a pretty simple matter really.
You didn't have an engine big enough to pull up a mountain grade COMFORTABLY. Meaning YOU weren't comfortable; the engine likely was doing just fine. If you have a "tow package" the transmission should be fine too.

And looking at the picture, wind resistance might be as big a factor as sheer weight.

[Fordlover]

Agree with others, you are driving it wrong. I've never been afraid of RPM's and personally I like to hear the V8 sing. I've got the 2 valve version of your engine mated to a 5 speed auto/3.73's and it is more than adequate to move 5,000 lbs. of camper.

You don't mention what gears you have, but the tow package trucks were rated to > 7,000 lbs.

[rexlion]

My only qualm about towing that fast up mountain grades is the transmission temp, not at all the engine. 4000-5000 rpm sounds horrible compared to what you're used to hearing, but it's not bad for the engine. But really I think you need to lower expectations from the 65-70 mph range, because slowing down while towing & climbing is not at all a bad thing for your transmission.

If the rev noise bothers you, just back off to 55 or 60. Or trade it in for something with a turbo die$el.

[blt2ski]

That part of I90 is all of 3000' max elevation, and a max grade of 4% from Seattle to vantage going east out of gorge, then you are in the 5-6% range, Still under 3000' elevation! You have only lost at best 10% hp in a natural aspirated motor.

As other have said, let it rev! Even a diesel on these grades will be in the 70-80% of its rpm if at max load, and slowing down!

Worst grade out of seattle per say, is the grade to HWY 18 from Preston, then the last 100-200 yds after exit 51, to the actual summit. The rest is not too bad.

Marty

[Turtle_n_Peeps]

Here's the deal.

You want to go up a hill fast in tow? You have to make the most HP your engine can put out. With that little Ford you need to wing the thing to make the most HP.

People really need to stop worrying about RPM. "ALL" throttle by wire engine have NO red line. It's all regulated by the ECM. It's not like the dinosaur days where you had to watch your tach or you're going to blow up your engine by too many RPM's.

Just to give you an idea of how little you're winding your engine: I have a 9.4 liter engine that I shift at 6,900 RPM. That engine has pistons as big as coffee cans. It's designed and built to wind that high and your little engine is built to wind 5,500+ RPM to make it most HP.

Even then, your little engine does not put out that much HP. Depending; it makes low 200's to high 200's. Get it up to 6,000 to 8,000 feet and now it's making High to mid 100's. That's not much HP to do much of anything.

In short: Plant your right foot to the floor until you get to the top of the mountain. :B

[jimh406]

Thanks for all of the comments so far. It helps me understand what's going on.

I suppose I should expect more revs if I was to tow with it. I didn't tow with overdrive off. Sounds like that might have helped. I also didn't try Premium this trip although I do have a basic tuner to adjust for tire size and I believe I can change octane as well. The tires btw are barely larger than stock for the Limited model which I have. I also do have the factory tow package.

True that I've been driving a diesel of one form or the other for the past 11 years. Also, it sounds like my diesel will more easily do the job and even in F450 trim, I can expect better mpg than the Explorer at 4000 or more RPMs. Also, with less wear and tear.

Sounds like some of you aren't familiar with a drift boat. The only motor is an electric along with the battery for that. I figured 200 lbs for the electric plus Group 24 batteries.

Once upon a time, I remember seeing the weight on the Willie site at around 325 for a 16x54. Mine does have the UMHW bottom, so figure some weight for that let's call it 500.

I figured 400 lbs for the tires. Maybe it's high, but either way, it's not a heavy load for an Explorer that is rated to tow much more.

Here's a picture of the subject boat and trailer.



A video of a driftboat in action is below. In a river, it's about steering the boat with the oars. Nope, not mine.

If you don't like the music, hit mute before you watch!

https://www.youtube.com/watch?v=htjBaOeRVUc

[rjstractor]

JimH wrote:
My guess is the driftboat/trailer with tires was still no more than 1500 lbs and probably closer to 1000. Those of you who tow with yours, should I expect high revs to maintain 65-70 going up mountains with this type of load? How many RPMs should I expect up to 6000 ft?

I'm guessing what is going on is a combination of knowing your actual weights and managing your expectations. I think weight estimate is rather low. I'm on a rescue team that uses basic 16' aluminum jon boats with 25 hp outboards for flood rescue. Boat and motor combined weigh over 600 pounds with a tank of gas. That's a basic boat, doesn't even have a battery in it. Add a trailer and you're at 1000. Your driftboat, if it has a decent size motor with forward controls could easily be 2500-3000 pounds going down the road. If it is that heavy, that's enough weight to make a small V8 really rev, especially trying to run 70 up a 6% grade. You might be much happier if you either slow down to 55 on the hills (probably won't make you happy), trade your Explorer for a new Ecoboost Expedition, or continue to tow with your diesel F450.

[KD4UPL]

Assuming you have the 3 valve engine a little internet research says it makes maximum torque at 4,000 RPM. That would be your best RPM for towing up a mountain. It doesn't make it's maximum rated HP until it hits 5,700 RPM.
How many RPMs were you turning? I'd guess not nearly enough.

[theoldwizard1]

I am betting you do NOT have the factory HD trailer tow option !

If you are concerned about damaging the engine/transmission install an auxiliary transmission cooler and a temperature gauge.

BillyW wrote:
My older (97) 4.6 definitely didn't have enough pluck to tow our 6000ish lb trailer through the mountains until I upgraded the rear end from 3.55 to 4.10.

A excellent solution !

OP probably only needs a 3.73 axle unless he is going to be pulling more loads than he said.

[dodge_guy]

You were not driving it correctly. I think you may have been worried about it revving too high. Let it wind out. Upper rpm is where it makes its power, 4000+rpm isn't out of the question! However with that lite a load it shouldn't have been working hard at all.

[naturist]

Normally aspirated gas engines both lose power at altitude and need to rev up to reach peak torque needed for dragging stuff uphill. There's not enough info in the OP, however, to determine if the truck has a problem or the driver has unrealistic expectations.

[TurnThePage]

My older (97) 4.6 definitely didn't have enough pluck to tow our 6000ish lb trailer through the mountains until I upgraded the rear end from 3.55 to 4.10. After that I had to get used to the high rpms, but it did the job reasonably well. On edit, I should have added that my setup had the old 4 speed auto. Dunno if Ford had upgraded to 6 speed by the 2006 model years

[rowekmr]

I used to tow my 26' boat with a 06 Explorer Ltd 4.6l and that 3 valve engine is a strong engine (same engine in the Mustang GT then) but as others say it loves to rev to make power. When I would take inclines towing that boat the 6sp trans would downshift and the engine would really sing but I must admit I liked that V8 sound.
I never had it in the mountains but it never let me down towing.

[bguy]

The most worry you have with high rpms is old accessory belts.

[shum02]

I have a 4.6L 2V Triton in a 98 F150 that I pulled a 4500lb HTT with and I'd downshift into 3rd and lay into the throttle.

The Tritons love to rev, LET THEM! With good oil and clean fuel it'll work at 4k RPM all day long. BTW they also love Premium fuel with NO ethanol for towing 🙂