Steve and Mike Smith (no relation, I presume) wrote:

> 1. Consider a car with a fuel computer fitted and use the
> information supplied.
>
> 2. As above but disconnect the fuel computer thus giving a raw
> transducer output and reinvent the wheel.

and

> Steve's solution seems best for cars - especially when you
> consider that every car made in the last 10 years would have the
> computer/transducer already, just to meet exhaust emission
> standards. Only the up-market models give a mpg / l/100km readout
> though, so intercepting the blips the transducer produces and
> converting to liters would be necessary.

Guys:

I don't think that cars with digital "miles per gallon" displays have
flow meters in their fuel rails.

I mean, think about it... If YOU were designing a fuel-consumption
display for a fuel-injected car, would you get the information by
installing two expensive flow-meters, measuring flow to the
injectors and subtracting the flow back FROM the injectors, or would
you go for the software-only method of simply accumulating the widths
of the injector pulses and multiplying that by the known flow rate of
each injector?

I know which method _I_ would use...

-Andy

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