Towing in OD OK with this situation?

[Ming15237]

Re: Towing in OD OK with this situation?

As an ASE master technician I will say for certain that you will not damage the transmission by towing in OD. as long as the transmission is not hunting for gears constantly you are and will continue to be fine. Tow haul mode on transmission simply increases the pump pressures inside the transmission and makes it shift more firmly. It also downshifts the transmission when slowing and downshift the transmission much sooner when accelerating so it does not lug the engine. On my yukon which has a digital temp gage for the transmission does not drop transmission temp at all by putting it in tow haul mode, it actually increases temps a bit. Temprature is second in importance to transmission slippage, that's why they increase line pressures. I tow my 7200lb boat on the highway all the time in overdrive, and in normal mode as it increases fuel economy tremendously, I simply keep an eye on transmission and engine temps, if the trans starts hunting I put it in tow haul, and that causes it to hold gears longer with much less shifting. Hope this helps.

 

[ricohman]

Re: Towing in OD OK with this situation?

The 2005 4Runner has the 5speed ECT. It does not have a tow/haul mode.

 

[Ming15237]

Re: Towing in OD OK with this situation?

I am aware that he does not have a tow haul mode button on his 4runner, I was simply informing him what the others were referring to when speaking of this feature. That being said my answer remains the same.

 

[Dr. Evil]

Re: Towing in OD OK with this situation?

The technique sounds fine. I used a similar one when towing my vette around on 300 - 400 miles trips each way. Behind a Sonoma. I got on avg 16-17mpg with the vette behind me. I did add an external trans cooler and guage along with replacing the heavy belt driven clutch fan with electric cooling fans. 17mpg doesn't seem out of the question to me.

 

[kenmyfam]

Re: Towing in OD OK with this situation?

Big additional tranny cooler and staying out of overdrive when towing over 60% (ish) of my vehicles capacity has not let me down yet.
Fuel economy sucks either way and staying out of O/D has cost me a lot less overall than my neighbor who swears by using O/D towing his travel trailer and blew 2 trannies.
Just my thoughts and findings though.
Are we talking U.S. gallons here or imperial gallons with the mpg ???

 

[ricohman]

Re: Towing in OD OK with this situation?

Big additional tranny cooler and staying out of overdrive when towing over 60% (ish) of my vehicles capacity has not let me down yet.
Fuel economy sucks either way and staying out of O/D has cost me a lot less overall than my neighbor who swears by using O/D towing his travel trailer and blew 2 trannies.
Just my thoughts and findings though.
Are we talking U.S. gallons here or imperial gallons with the mpg ???

Some vehicles cannot tow some loads in OD. And the converter keeps locking and unlocking and the temps continue to rise, eventually killing the tranny.
The 700R4 is a great example of this. Hook on a load and tow in OD and watch the temp creep up. I've rebuilt dozens of these and there are many ways to keep a 700 alive.

 

[jkust]

Re: Towing in OD OK with this situation?

As an ASE master technician I will say for certain that you will not damage the transmission by towing in OD. as long as the transmission is not hunting for gears constantly you are and will continue to be fine. Tow haul mode on transmission simply increases the pump pressures inside the transmission and makes it shift more firmly. It also downshifts the transmission when slowing and downshift the transmission much sooner when accelerating so it does not lug the engine. On my yukon which has a digital temp gage for the transmission does not drop transmission temp at all by putting it in tow haul mode, it actually increases temps a bit. Temprature is second in importance to transmission slippage, that's why they increase line pressures. I tow my 7200lb boat on the highway all the time in overdrive, and in normal mode as it increases fuel economy tremendously, I simply keep an eye on transmission and engine temps, if the trans starts hunting I put it in tow haul, and that causes it to hold gears longer with much less shifting. Hope this helps.

I wished my SUV's had tranny temp gauges like so many do. Even some of the junkiest 4 cylinder GM cars have factory tranny temp in the information center. That would pretty much prove or disprove my original point. I wonder if that can be added on? Back to the tailwind situation, I take the same route every time and again, with the wind, it doesn't drop out of OD and other times it can't make it up a hill without a coming out of OD. Like it's a totally different vehicle. It is surprising how much the wind affects my truck's performance while towing. I always tow with a cover but interestingly, I had read an interview of professional fishermen who tow 10's of thousands of miles a year and they don't use covers.

 

[oldjeep]

Re: Towing in OD OK with this situation?

I wished my SUV's had tranny temp gauges like so many do. Even some of the junkiest 4 cylinder GM cars have factory tranny temp in the information center. That would pretty much prove or disprove my original point. I wonder if that can be added on? Back to the tailwind situation, I take the same route every time and again, with the wind, it doesn't drop out of OD and other times it can't make it up a hill without a coming out of OD. Like it's a totally different vehicle. It is surprising how much the wind affects my truck's performance while towing. I always tow with a cover but interestingly, I had read an interview of professional fishermen who tow 10's of thousands of miles a year and they don't use covers.

Couple thoughts
1) Tranny temp guage is easy to add, but generally requires you to remove the pan. Some have a rubber press in bung, the ones I've used are weld in.

2) Cover or no cover - I suspect that this has a lot to do with the overall aerodynamics of the tow vehicle and boat.

3) Wind - even in my 400HP 1/2 ton truck, I notice the impact of a headwind on my milage and how the tranny shifts. Add in a trailer and it is that much worse.

 

[ricohman]

Re: Towing in OD OK with this situation?

I wished my SUV's had tranny temp gauges like so many do. Even some of the junkiest 4 cylinder GM cars have factory tranny temp in the information center. That would pretty much prove or disprove my original point. I wonder if that can be added on? Back to the tailwind situation, I take the same route every time and again, with the wind, it doesn't drop out of OD and other times it can't make it up a hill without a coming out of OD. Like it's a totally different vehicle. It is surprising how much the wind affects my truck's performance while towing. I always tow with a cover but interestingly, I had read an interview of professional fishermen who tow 10's of thousands of miles a year and they don't use covers.

You can certainly add a temp gauge. The sensor is usually installed on the output line. I try and install it as close to the trans as I can.

 

[Reel-hip]

Re: Towing in OD OK with this situation?

I am one that disagrees with towing in OD. You have a different tow vehicle than I and a lighter boat but I believe the theory is the same. I have an older F350 diesel. I went thru 5 transmissions. My truck is only a tow vehicle. My 25 ft Skipjack fully loaded with fuel and gear is pushing 10,000 lbs. I would tow in overdrive and the transmission was never searching for an extra gear. My overdrive gear was heating up too much and caused a failure. I have hauled only in overdrive off for the last 3 years and have had the same transmission with no issues. I do want to say I believe the ford transmission (E4.0-D) is not designed for my turbo charged transmission but I also don't think it's a coincidence that the transmission has lasted this long if I was towing in OD.

 

[Ming15237]

Re: Towing in OD OK with this situation?

I will say back in the day we saw a lot of those transmissions fail, they really were not very good from the get. Compared to modern day American transmission they were a 2 on a one to 10 scale for durability. The torq put out by the 7.3 was simply more than those transmissions could take and the heat the the OD Put on it was not any help. By comparison, I have never seen a 4runner pop a transmission, they are a VERY STOUT transmission. But again no matter how tough a trans is you MUST use good judgment.

 

[spoilsofwar]

Re: Towing in OD OK with this situation?

As to the OP's MPG claims, I will just add this:

Towing my 19' 6" Stingray (probably almost the same weight as OP's), my tired '99 F150 w/ 4.6 V8 gets maybe 13ish MPG. My wife's '06 Pathfinder (4.0L V6, factory tow package), on the other hand, only sees about a 3mpg drop in fuel economy when towing the boat on the highway (it gets ~17-18 mpg according to the dash). The Pathfinder barely notices the boat back there; the F150 never lets me forget it.

So, I don't find his claims to be out of the ordinary, personally.

 

[Fleetwin]

Re: Towing in OD OK with this situation?

Temperature, region and alcohol content play a very big role in MPG numbers.

My Lincoln EcoBoost will show a difference of 100 miles on the distance to empty setting depending on if I get 10% alcohol fuel or pure gasoline. The vehicle can read the alcohol content in the fuel. As an example, Valero fuel never gets me more than 330 miles to empty. Chevron gets me about 450 miles to empty. I have learned to avoid stations with high alcohol content fuels.

The Lincoln gets 25-26 MPG not towing and 17-19 towing a 3500# Larson. The vehicle weighs 4500# and is AWD.

The Power and economy are amazing. It is a rocket. I now have 40000 miles on it.

 

[NYBo]

Re: Towing in OD OK with this situation?

The difference in energy content between E10 and straight gas is very small (less than 5%, IIRC), and doesn't account for the differences in fuel economy you noted. Something else is going on.

 

[Ming15237]

Re: Towing in OD OK with this situation?

Temperature, region and alcohol content play a very big role in MPG numbers.

My Lincoln EcoBoost will show a difference of 100 miles on the distance to empty setting depending on if I get 10% alcohol fuel or pure gasoline. The vehicle can read the alcohol content in the fuel. As an example, Valero fuel never gets me more than 330 miles to empty. Chevron gets me about 450 miles to empty. I have learned to avoid stations with high alcohol content fuels.

The Lincoln gets 25-26 MPG not towing and 17-19 towing a 3500# Larson. The vehicle weighs 4500# and is AWD.

The Power and economy are amazing. It is a rocket. I now have 40000 miles on it.

Almost every vehicle manufacturer recommends ONLY Top Tier fuel be used in their vehicles. Top Tier Gasoline
The advantages of this fuel are in the link provided. Additionally, fuel containing high levels of ethanol can and does reduce fuel economy. Ethanol is the single most destructive additive ever added to gasoline that we in the automotive industry have ever seen. The effects are even greater in the boating environment due to the constant presence of moisture present in the boating environment which causes phase seperation with the ethanol and gasoline. Phase Separation in Gasoline
This all being said higher levels of ethanol in the fuel will reduce fuel mileage, but no where near the levels you are seeing. Now if you were to run E85 fuel, also known as "flex fuel" you will generally se a reduction in economy in the 20% range which could come close to your fuel mileage decrease.

 

[bigdee]

Re: Towing in OD OK with this situation?

Almost every vehicle manufacturer recommends ONLY Top Tier fuel be used in their vehicles. Top Tier Gasoline
The advantages of this fuel are in the link provided. Additionally, fuel containing high levels of ethanol can and does reduce fuel economy. Ethanol is the single most destructive additive ever added to gasoline that we in the automotive industry have ever seen. The effects are even greater in the boating environment due to the constant presence of moisture present in the boating environment which causes phase seperation with the ethanol and gasoline. Phase Separation in Gasoline
This all being said higher levels of ethanol in the fuel will reduce fuel mileage, but no where near the levels you are seeing. Now if you were to run E85 fuel, also known as "flex fuel" you will generally se a reduction in economy in the 20% range which could come close to your fuel mileage decrease.

True and factual......ethanol does not belong in gas

 

[Rancherlee]

Re: Towing in OD OK with this situation?

I could believe it on a lighter covered boat. covered 17-18' aluminum boats never dropped my mileage more than 3-4mpg with my old 4.6L V8 Mountaineer (from 19-20 to 16-17 highway @ 60mph) What I don't believe is that his was holding OD when his buddies Eco-boost couldn't maintain speed on a hill, that had to have been one HECK of a hill for the eco-boost to loose speed on. I've got the 5.0L in my new F150 and climbed some pretty dang steep hills towing 7500#+ of skid steer behind me an not once have lost speed on a hill, and the Eco is a step above my 5.0L for pulling (although gets worse mileage towing than the 5.0L)

 

[ricohman]

Re: Towing in OD OK with this situation?

I could believe it on a lighter covered boat. covered 17-18' aluminum boats never dropped my mileage more than 3-4mpg with my old 4.6L V8 Mountaineer (from 19-20 to 16-17 highway @ 60mph) What I don't believe is that his was holding OD when his buddies Eco-boost couldn't maintain speed on a hill, that had to have been one HECK of a hill for the eco-boost to loose speed on. I've got the 5.0L in my new F150 and climbed some pretty dang steep hills towing 7500#+ of skid steer behind me an not once have lost speed on a hill, and the Eco is a step above my 5.0L for pulling (although gets worse mileage towing than the 5.0L)

Perhaps the ecoboost owner was slowing to keep his truck in OD. I've driven a 2012 with 9.5k in tow. I couldn't believe the power that thing has and I drive a 2010 6.8 V10 F350. No way any 4runner has the power to run with a new ecoboost. Two different worlds there.
However the ecoboost could not match the economy of my V10 and I was towing nearly 4k more. The boosted motor is thirsty under load, but that would be expected.

 

[Ming15237]

Re: Towing in OD OK with this situation?

I am pretty sure the ecoboost was loosing speed due to the shear weight he was towing compared to his relatively light boat. That being said I did testing for Ford on the ecoboost prior to its release to the public, and I will say that it is a real BEAST! There is not much that will out pull those trucks that is not a diesel! That being said I have a Yukon Denali with a 6.2 v8 with 400+hp and that ecoboost f150 will out tow that truck with my boat hooked to it which is 7200lbs. Now my 2008 Silverado duramax dully is a beast! That thing is rated for 21k and handles the boat like its not there. This all being said anything can tow the 3500lb boat of the OP's in OD as long as it does not shift from gear to gear.

 

[Fleetwin]

Re: Towing in OD OK with this situation?

The difference in energy content between E10 and straight gas is very small (less than 5%, IIRC), and doesn't account for the differences in fuel economy you noted. Something else is going on.

Yes there is. Gas stations that sell one thing and report another. Also, how is it mixed. "Splash" (during delivery) or "Refinery Mix".

A big difference. The same holds true for bio diesel. One day you get 5% bio, the next day 60%+.

I stick with nationally known brands of fuel. Chevron, Shell, etc. I've learned to avoid the jippo's.