ATF Burned!

Is this when the engine stops working? Asking for a friend.

 

If someone doesn't know what engine braking is, they probably shouldn't be towing more than a hot dog cart.

 

Ok.so can you enlighten the community?

 

You’re proving my point. The whole internet available to you... here is a decent explanation-
The Ins And Outs Of Engine Braking
Here's a quick low-down on how engine braking occurs in petrol and diesels engines, along with where it can be utilised!

The art of engine braking can either be a help or a hindrance when driving, exploiting the suck, bang and blow of internal combustion in an inverse form. Experienced when acceleration has stopped and at 0% throttle, engine braking can be used to slow a car down as much as possible in tandem with the brakes. Engine braking can make coasting while off the throttle slightly frustrating as it saps your road speed at a rate that needs further throttle input down the road. But it does have its uses, so let’s take a look at how engine braking occurs and how it works in petrol and diesel engines.

In its simplest form, engine braking occurs in a petrol engine when the throttle is released. When the throttle pedal is actuated, a butterfly valves opens at the engine’s intake, allowing air to enter the intake manifold to be mixed with fuel for combustion. So when the throttle is released, this butterfly valve shuts, allowing only a very small amount of air through to the engine.

This sudden closing of the airway forms a vacuum within the intake manifold which produces an opposing force to the pistons reciprocating within the engine. Imagine placing your finger over the end of a football pump and then trying to move the plunger upwards - a large opposing force formed by a vacuum within the cylinder will mean that the pumping piston won’t shift much at all.


The effort that the pistons have to exert to oppose the manifold vacuum saps energy from their reciprocation, forcing them to slow down and thus rotating the crankshaft slower, reducing road speed. This braking is therefore emphasised when engine speed is high as the large amount of air previously entering the cylinders is suddenly shut off, creating the vacuum that opposes a higher rotational force from the cylinders.

On top of the vacuum element, a minimal amount of engine braking is also achieved by friction between the moving parts of the engine. Although the oil system provides a more than suitable amount of lubrication to make sure the moving components don’t end up welding themselves together due to heat, there is natural friction between every moving piece of the engine as they interact with each other. This friction has a negative influence on the positive energy of the moving engine, thus stripping rotational energy from the crankshaft and ‘braking’ the engine.

(article by Michael Fernie @ carthrottle.com)

 

What is petrol? Is it an additive to keep ATF cool?

 

I think it's a Canadian blend of gasoline.

 

Lol your funny so how does s4 help with breaking in normal driving and not hills? I just think its funny how you take a bullet point and its set in stone for s4.

 

Us Canadians use a special blend of Unicorn piss and Eskimo sweat in our petrol , We keep it cool in our igloos so it lasts longer

 

I inderstand this im just saying the manual does not say you must tow in s4 its a bullet point for downhill grade control to have engine slow you down instead of torching breaks and ending up in a ditch

 

It’s not in stone - it’s in a written manual authored by Toyota. Take the advice or don’t - I don’t care. FWIW I use D while towing on flat ground but that doesn’t mean that is what Toyota recommends. What does the bullet point have to do with anything? Do bullet points mean they don’t really mean what they wrote? This section of the owners manual is a list of tips for driving while towing. You can take the tip or not but doesn’t change the fact it’s there and says what it says.

 

That’s inaccurate.

 

I love the passion!! I will be waiting for the results so we can put this aux cooler nonsense to rest

 

This sounds like the driver doesn't have any control over whether the truck engine brakes or not. Therefore, I would always tow in S4 to be safe.

 

I hope so, but doubt it.

 

What is the benefit of towing in S4 besides engine braking?

 

Keeping the transmission temp down. Shifting into and out of overdrive builds heat fast.

 

Post # 129

 

Thanks...but I thought lock up was better for reducing heat load?

 

It is. It was either a mistake or they were just wrong.

 

It is. More likely to stay locked in 4th than 5th or 6th.

 

Correct, slippage while unlocked is the source of heat.

 

Alrighty...squared away now. thanks!

 

My apologies for the false info, I stand corrected and humbled.

 

I haul things, I need 4x4,...I mean towing is not the only reason for having a truck...

 

You can haul things in a mini van and have more payload though....

 

Anyone with a 19+ check the atf thermal degradation estimate?

 

Who wants to haul a load of gravel/dirt/mulch in a mini van lol.

 

It sounds like you used to have lunch with my brother!!

 

Tracks? There are no tracks where we're going!

...I did use S4 this weekend to tow the boat on a highway with 75mph speed limits. Now deciding between running 1,000 RPM higher or frequent ATF changes are the better option.

 

What’s the purpose of tow mode if one is using S4? Thought the whole purpose of tow mode was for the truck to pick the correct gear/rpm while towing.