Just increased my mpg's from 14 - 18.25

I get a higher MPG instant read out on my scangauge when I am coasting out of gear versus in gear every single time I have tried it.

I have a long hill up the road from me and coasting along in 6th gear doing around 50 mph the scangauge will show somewhere around 64 MPG, as soon as I slip it out of gear the tach will drop to 1200 RPM and the readout will immediately jump to 86 MPG or better.

That tells me that my truck is using more fuel coasting in gear then if I am coasting out of gear.


If someone wants to read the page that says that can't be to my truck, have at it, it is sitting in the driveway out front and I'm sure she'd love to hear a bedtime fairytale read to her

 

another hypermiling trick is to take foot off the gas pedal as soon as the brake lights of the car in front of you comes on.
another trick is to pulse drive (stepping on gas on and off). I think this is mostly used in hybrid but certainly will help in gas only engines as well.
the basic principle is to coast as much as possible.
hypermiling works.

 

don't you get mpg reading of 9999 if you coast in gear?

 

I just cruise control at 65 mph and clutch in going downhill, then resume cruise control when speed returns to 65 mph. I consistently get 16-17 mph highway with long travel

 

when you get the 9999 reading, you are no longer 'coasting'...you are engine braking, and thus, slowing down quicker than if you were 'coasting' in neutral. It depends on the situation. If it were a steep down grade, I would engine brake, if it were a slight downgrade, I would clutch in or just remain cruise control in gear.

 

I run an Over the Road Trucking company and we are gunning for 8 mpg by mid summer... tall order, when the average Detroit Diesel is racking 5.7-6 mpg in our application....

We are up to 7.8 in a couple of trucks, and the fleet is pushing 7 mpg as a whole... one big change to our Trailers, and we will bust past 8 and shave away some of the 43K per month in fuel....

..anyway, I just bought a $50 video from the Smith System to help our driver's behavior towards better fuel economy. Video was dissapointing, but there is a 6 minute clip on their website that contains the meat and potatoes of the video for free anyway.....

In a class 8 rig, driver behavior accounts for 35% of fuel economy, and the balance is equipment....

I used to get 22 mpg from the factory, but my newer, bigger, heavier AT tires have cracked me down to 18.....

Check out the Smith System stuff for some good on road tips for safety... and share with your wives....

Matt

 

ok, if 9999 is the highest mpg reading while it is in gear, how can going in neutral get a higher mpg reading? that is what I am trying to get at.

 

It all depends on the grade of the hill. At the point where engine braking gives you 9999 mpg, then it will be more fuel efficient than neutral because the fuel delivery is halted. However, in a level straight-away when you are coasting to a stop, then there may not be enough momentum for your engine to cut off fuel delivery, and thus neutral may have a higher mpg reading. It all depends on the situation, but in gear usually has a higher mpg.

 

I was referring to the above statement, that he sees a higher mpg instant readout with neutral vs in gear, with means he must not be getting 9999 when coasting in gear? I know I get a reading of 9999 when coasting in gear.

 

I do get a 9999 if I am coasting over 60 mph

How often you see 9999 on the scangauge all depends on where you set the fuel cutoff during the initial setup

 

I use the default cutoff value of 24 and so far get accurate mpg value on every fillup.

 

whats with debbie downer here?

no offense man, but if the guy is happy hes getting better gas mileage then let him be happy..

i love my tacoma and wouldnt trade it in for anything, yet if i can get 50mpg on this thing, i would, then that means more money in my pocket for mods or what-not, just because i drive a truck doesnt mean i want to blow all my money on gas...

 

Absolutely correct!

 

The Prius Hybrid also has a coolant storage tank that is much like a thermos bottle. It can store warmed up coolant for quite a while (two plus days at about 180f). This can be circulated through the cylinder head by valving and an electric pump. This helps preheat the engine for a quick warm up. They do this mainly for cold start emissions control also as the cold start up out gasses are the highest emissions on most vehicles.

As for fuel cut. This has been common fuel saving programming on modern vehicles for years. The details are important. The main job of an engine management system is to keep the catalyst happy (good cat food if you will allow the pun) in order to keep emissions low. Due to the fact that the efficiency of the catalyst degrades as it cools down (no fuel flowing through the engine) on long decelerations there can be a need to turn the fuel back on to keep it warmed up. That way when you get back into the accelerator the catalyst can handle the extra load from the increased flow. This is known as a tau cut (or cut of fuel cut). Sometimes you can watch it happen in engine data. That also makes sense because excess O2 in the exhaust stream poisons the reduction portion of the catalyst causing an increase in NOx. Since the reload of the engine does not jump right into maximum NOx production (under normal conditions) it can re-stabilize before there is "punch through". The reason that I mention this is because of the engine out there that actually do shut down cylinders. They not only shut down the injectors, they shut down valves in a manner to shut of the air flow through the cylinder as well. This way, the ones that are still running supply normal gas flow to the converter without the air being pumped in by the shut down holes.

HTH.

 

You can coast effectively in gear when you're going slower by placing it in a higher gear. For example, at about 30-35, I put the transmission in 6th gear and take my foot off the pedal. It coasts pretty well without much engine braking, plus you get the advantage of less fuel.

 

I don't think pulsing would work, if by pulsing you mean accerating to a speed and then coasting and repeating between a certain range (e.g. accelerate at 60 and coast at 70, then repeat). It should always take more fuel to accelerate than to just hold a speed (e.g 65) because you're trying to overcome inertia and friction. Maintaining a speed should use less. Now if you accelerate before a hill and then coast just before you crest, you might see some benefit.

 

Unless you're downshifting at really high rpms (your rpms are high before you downshift), I doubt it does any harm. Technically, you're engine braking everytime you take your foot off the gas.