Quote:
Originally Posted by Isaac Zachary
I don't quite understand what you're saying. Fresh air needs fuel. The engine shouldn't be pouring in more fuel for recirculated exhaust gases. So if it assumes all airflow is fresh then that's a good way to measure fuel, as long as the AFR is the same since the EGR system isn't going to affect how much fuel is added to the fresh air.
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Just to clear up this bit, my car is a speed density setup, no MAF, only a MAP sensor.
When EGR is disabled (initially at warmup) the figures match the car mostly
Yet when EGR is enabled, manifold pressure increases, despite similar fresh air 'intake', Torque doesn't know the ratio of fresh air - exhaust gas, and thus assumes more fuel is being injected and Torque's MPG figures drop when warmed up.
If only there was a proper fuel flow PID standard on OBD2
Thanks for the rest of the post, i guess the timing acts as engine braking quite well, high performance VW DSG gearboxes 'fart' as timing is retarded during each gearshift (which happens very quickly) as closing the throttle and adjusting airfuel ratio would be far too slow.