Will it cause any issues in the LR3 if I coast in neutral gear for a long time?

[paula]

I live in the hilly regions of LA and my mpg is pretty bad. I was thinking that if I coast downhill in neutral in a safe manner, I can save a lot of gas and make up for the return uphill drive.

Are there any potential issues to the LR3 for such neutral coasting? Thanks

 

[Houm_WA]

Less control of your vehicle and harder on your brakes when it's time to slow/stop.

 

[jaamrode]

When in gear and going downhill and not pressing on the accelerator you use zero gas, as long as the engine rpm's are above the idle set point. With the use of computer controlled engines, injectors do not operate while coasting. If you put it neutral the engine has to idle causing you to use more fuel than if you were in gear.

 

[toddjb122]

When in gear and going downhill and not pressing on the accelerator you use zero gas, as long as the engine rpm's are above the idle set point. With the use of computer controlled engines, injectors do not operate while coasting. If you put it neutral the engine has to idle causing you to use more fuel than if you were in gear.

Very cool. Did not know that.

 

[cannonball55]

When in gear and going downhill and not pressing on the accelerator you use zero gas, as long as the engine rpm's are above the idle set point. With the use of computer controlled engines, injectors do not operate while coasting. If you put it neutral the engine has to idle causing you to use more fuel than if you were in gear.

I'm not an expert, however a little common sense says this isn't entirely true.

IF the engine is turning (ANY RPM's) gas is being used. period. the amount varies but some is being used none the less.

that being said... shifting into neutral when going down hill does remove the load on the engine, causing a decrease in the RPM's, a decrease in RPM's would as one would expect: use less fuel.

however, i would expect that the savings would not particularly be worth the added stressors shifting in and out of gear would cause (along with the brakes etc)

 

[jwest]

Well, you can often coast in N faster than if in gear. Being in gear will act like a slow brake, which then requires more throttle sooner than if rolling with almost no resistance from the engine and drive train. I do it all the time in mine because it's so heavy.

The braking issue some people mention is silly. My brakes last over 50,000 miles easily because in town I'm not blasting away only to hit the brakes at the next light.

The best thing is to coast into the next hill,, which is probably what Paula is wanting to do.

I'm going to test something this weekend: the safety feature DSC in corners comes on if pushing too hard into the corner. I want to see if it engages the same way in N vs D.

 

[jaamrode]

Here is an article from popular mechanics also stating you use no fuel while coasting

http://www.popularmechanics.com/cars/hybrid-electric/a5977/coasting-in-neutral-fuel-economy/

Just because the engine is turning doesn't mean it is getting fuel. The computer controls the injectors, which supply the fuel.

If you are going down hills where you don't need to brake to control your speed at the bottom bottom then I think it would be a wash at which is more economical. Coasting in neutral and using gas to make the engine idle while going down but not getting into the throttle as soon on the uphill side, or staying in gear and using no fuel going down but having to get on the throttle earlier due to engine braking.

 

[johnsoax]

Sorry... Not possible.. You are using fuel for the RPM's. The LR3 uses the engine to brake the speed of the truck going down hills..

To test your theory, go down a hill and then shut off your ignition, I bet you immediately slow down due to loss of power from the engine.

If his theory is correct, you won't slow down.

You have to ask yourself a few questions... How does the car know you are going downhill? Because there is still load on the engine.

 

[jaamrode]

If you don't believe my previous article, how about this one where they ask a engineer from Toyota.


http://m.caranddriver.com/features/...ng-to-a-stop-do-not-shift-into-neutral-page-3

 

[johnsoax]

If no fuel is going into the engine when you are coasting, are you still getting detonation? If not, why do you have exhaust sounds? From air moving through the system?