My friends don't think it does!
2007-09-03 23:33:46 · 5 answers · asked by Anonymous in Cars & Transportation ➔ Maintenance & Repairs
I will assume you are talking about an automatic transmission - because otherwise the difference between being in neutral or having your foot on the clutch makes no difference.
Being in Neutral DOES save petrol. If you leave it in gear and hold it on the brake, the engine is straining against the brake and trying not to stall. To do this, it has to work under a higher load, driving the torque converter and gearbox internals and using a different part of the fuel mapping. When it is under load it uses MORE petrol.
In neutral, it settles down to an unloaded state, and uses less fuel.
As a kind of aside - if you drive a manual car - when you decelerate in gear you use almost no fuel at all - far less then if you dip the clutch or coast in neutral. This is not related to sitting at traffic lights in an auto car because the engine is not fighting against the brakes/transmission - in actual fact the wheels turning the transmission keep the engine running with hardly any fuel needed.
Also - if you sit with it in gear, you will have to keep your foot on the brake, and the people in the car behind you get REALLY PISSED OFF BY THE BRIGHT BRAKE LIGHTS SHINING IN THEIR EYES!!!!
ha ha ha ha - sorry - personal gripe there!
2007-09-04 00:58:42 · answer #1 · answered by filski666 2 · 1⤊ 1⤋
Your friends are wrong, but its not safe to plan to do this. You may forget where automatic transmission shifter location is and accidently miss it with your hand when shifting into drive or "YIKES" reverse. As the car idles while in drive the torque converter although slipping is ingaged with the transmission and at the time is creating a very slight drag on the crankshaft lowering the RPM of the motor. When in neutral the torque converter still spins but is totaly dis-engaged with the transmission creating no drag.
You can prove this to yourself by watching the tachometer in drive at a stopsign. Pop it into neutral. You will notice the engine RPM raises slightly.
*You are very observent.
Think of your riding lawn mower mowing grass. The internal governor is constantly "hunting" and changing the throttle opening while mowing. Stop the mower with the blade spinning on top of the lawn. Disingage the spinning blades. The rpm of the motor increases. Anytime there is drag on a gasoline powered motor gasoline is waisted to overcome the spinning blade power loss due to the external drag on the engine. Cancel drag and efficiency and economy goes up.
If you want to toss your buddies a real curve bet them that fuel can be saved with less drag inside the engine with a roller bearing camshaft. Roller bearing lifters. Titanimum connecting rods and valves. Roller rocker arms. Forged aluminum pistons. Low drag light tension piston rings.
The object here is to lower frictional loss as the motor rotates through it's cycles. The lightweight internal parts allow the engine to accelerate quicker to a given rpm using less fuel.
2007-09-04 02:16:04 · answer #2 · answered by Country Boy 7 · 2⤊ 0⤋
switching to neutral actally wastes more feul than staying in gear. while in gear your vehicle is trying to move forward but the brake is preventing such movement but when you put your vehicle into neutral the engine runs at a higher speed "rpm" which then wastes more feul due to higher running speed.
2007-09-03 23:43:05 · answer #3 · answered by bravescotlandheart 1 · 1⤊ 0⤋
That's what I've always heard. Is it worth it ? Does it wear on the transmission ?
2007-09-03 23:53:45 · answer #4 · answered by Scorpius59 7 · 0⤊ 1⤋
how could it but it does cause unnessary wear on the linkage and tranny. pay me now or pay me later
2007-09-04 00:35:37 · answer #5 · answered by bungee 6 · 0⤊ 1⤋