Manual tranny - cruise to a stop or downshift?

[CBDFrontier06]

Coasting in neutral has left the engine to rely on fuel to keep itself running, so it's using fuel when coasting in neutral. Most modern fuel injected cars shut off the fuel supply when coasting in gear until RPMs slow to near-idle..then the fuel supply is restored. You'll use less gas using engine braking.

 

[blueiedgod]

I slow down, using brakes, in whatever gear I happen to be until the engine is at about 1000 RPM, and then I clutch and Neutral.

Brakes are cheap.

Clutch and synchros are not.

 

[caprice_2nv]

To me one of the biggest benefits of a manual transmission is being able to coast at idle. When I'm coasting or going down a steep hill I push in the clutch and let the engine idle, no point in keeping the RPM's up and wasting fuel. For me, doing a good burnout is the time to waste fuel, not coasting.

 

[msparks]

Match revs, don't use a clutch, I just pull it down at the right time and it goes right into gear. No problem.

Don't use the clutch much either to upshift. 4th gear is a booger sometimes so I will use the clutch going 3rd-4th.

 

[meep]

Originally Posted By: CBDFrontier06
Most modern fuel injected cars shut off the fuel supply when coasting in gear until RPMs slow to near-idle..then the fuel supply is restored.


I have wondered about this, and I suspect this may vary between manual and AT. It used to be the other way around. When coasting in gear, vacuum would be too high, resulting in incomplete combustion, so the throttle would be opened ever so slightly by the ecu to lower vacuum and clean up the burn.

M

 

[JustinH]

A guy on one of the saturn forums showed a datalog of a fivespeed saturn.

It cuts fuel when you coast to an idle in gear, it gives fuel when the shift lever is in neutral.