Most fuel efficient speed?

If you are driving 45 miles one way to work and you normally average 20mpg and by driving slowly and cautiously you get it up to 22mpg you will save about $8 per week. I am not sure it is worth the effort. If $8 per week is a big deal to you then you probably should be driving something cheaper and more efficient than a truck.

Truck and SUV owners stress too much over fuel economy. I bet very few owners of Honda Civics worry about getting 38mpg instead of 36mpg.....

 

I agree with you completely to be honest when gas in central jersey was 2.30 a gallon I didn't care as much about MPGs but once gas went to 3 and over started to become more interested in way to get the most of out my gallon with what I had to work with. Its a game to me it's been helping me pay more attention to maintenance which I hope will benefit me in the long run. Reason I won't go back to a car because I know this truck will get me to Point A & B safely. I've had couple accidents with it and walked out scratch free..I had utility to do yard work and side jobs make some extra cash.4 wheel makes it easier for me to be an emergency responder in the winter time, so for all the Postive ill take the cuts in mileage for fact the truck will have my back but like I said before if I can get 16+ out of it minus well at least try to.

 

You can cruise downhill at 60mph in gear and your injectors will be shut off, not using any fuel. MPH doesn't determine throttle position

 

What? Your injectors shut off?

Let me say this, I live in the upper Midwest where everything is pretty much flat. I use the Torque app to monitor my instantaneous and average MPG. On a good day with no wind, on a flat road, 40MPH is your best MPG. It will decrease as you increase speed from there.

Trying to factor in hills and throttle positions that accommodate inclines and declines in the road is crazy based on the original question.

 

Yes

 

This /\/\/\
55 mPH is breaking point for Airdrag. after that speed you burning more fuel to combat air then to make your truck move.

 

And how does the engine stay running when your injectors shut off? Injectors do not shut off.

 

Yeah, I would like to see some evidence to back up this injector shut off thing. I'm not buying it. Don't the injectors have to run even for idle????

BTW- hauling a 12' box trailer with about 1000 lbs in it, mostly highway, 75-80 MPH yields about 8mpg!!! Yikes!

 

Injectors DO shut off under certain conditions. Lockup torque converter on automatic, and via clutch on manual - rear axle turns the engine/transmission. Viewable via Scangauge. Computer turns injectors back on when TC unlocks, or if clutch is depressed, or when rpm gets near idle.

 

This ^^^^ Truth

 

45 for me

 

Sadly, that is a no. If your injectors actually DID cut off, your engine would not run. Period. No fuel = no engine running. Granted the injectors will only fire a limited amount of fuel, but no, it will never shut OFF the injectors. Perfect example: If you have an automatic transmission, and the injectors shut off, how do you get the engine to restart? You would have to rotate the engine. This can NOT be done in automatic transmissions of today.

The only case where injectors actually turn off are on the vehicles that are the 4-8 cylinder models where when at a steady cruise above 45 mph the computer will shut off 4 injectors, and actuate the lifter collapse system for short time periods.

If you were to not fire any fuel into the cylinders you would increase combustion temperature and NOx output.

 

it seems that people aren't defining the injectors shutting off very well, it's only when someone is downshifting i believe. When you downshift if your rpm's are above a certain point then the injectors will be shut off and the engine will be driven by the rear wheels. Then once the rpm's go below that certain point the injectors will turn back on, and yes this is only in a manual.

This is all my understanding from what I've been told here, I may be wrong.

 

It cannot be done that way. an automatic transmission is unable to turn the engine. The torque converter only works one direction, not to mention you have over-run clutches and the like. Even in a manual transmission, if it were to actually shut off the injectors, the engine would die, and it would be like taking your foot of the accelerator in gear. You would slow down VERY quickly. Yes, the computer does reduce the fuel that is being injected to an acceptable low level (Equivalent to idle speed, or slightly higher) but the injectors are never actually turned off, even in a manual transmission.

 

95 km/h will keep your rpms below 2000. I find that's the optimal speed and rpm.

 

My understanding was that you had to be over 2200 rpm, IIRC, and had to be completely off the throttle while in gear for the injectors to shut off, so you are basically working on coasting to a stop or down a pretty steep hill for this to take affect.

 

I get up close to 25mpg doing 65.

 

So you're saying roll thru stop signs and run into other cars at a stop light?

 

We went in search of an expert opinion on this one. According to Paul Williamsen, the product education manager at Toyota, “All contemporary Toyota and Lexus vehicles (and every other car built since the 1990s that I’ve looked at) can detect the condition when engine revs are higher than idle with a fully closed throttle: Under these conditions, all current to the fuel injectors is stopped, and no fuel is injected.” That means if your foot is off the gas while the car’s in gear, you’re not using any fuel.

Tom Read, GM’s powertrain spokesman, agrees: “Shifting into neutral in an automatic will cancel fuel cutoff. Thus, it is better to remain in gear and let the drive wheels pull the engine airflow down to where fuel cutoff can be enabled or where fuel flow is minimized.”

http://www.caranddriver.com/feature...-do-not-shift-into-neutral-page-3?redirect=no

 

Bueller ?