bbaker2001
Apr 11, 2017Explorer
rpm when towing
When towing with my ram diesel how do I tell when I should downshift. it seems to tow so easy, but slows when going uphill at 60 what should my rpm show.
4x4ord wrote:
Wikipedia explains how the air fuel ratio in direct injection gasoline engines can vary from ultra lean (as lean as 65:1) to stoichiometric to slightly richer than stoichiometric during full power.
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Edit: I copied and pasted the part that of the write up that explains ultra lean operation:
Ultra lean burn or stratified charge mode is used for light-load running conditions, at constant or reducing road speeds, where no acceleration is required. The fuel is not injected at the intake stroke but rather at the latter stages of the compression stroke. The combustion takes place in a cavity on the piston's surface which has a toroidal or an ovoidal shape, and is placed either in the center (for central injector), or displaced to one side of the piston that is closer to the injector. The cavity creates the swirl effect so that the small amount of air-fuel mixture is optimally placed near the spark plug. This stratified charge is surrounded mostly by air and residual gases, which keeps the fuel and the flame away from the cylinder walls. Decreased combustion temperature allows for lowest emissions and heat losses and increases air quantity by reducing dilation, which delivers additional power. This technique enables the use of ultra-lean mixtures that would be impossible with carburetors or conventional fuel injection.