If you don't rev match then when you down shift your revs will be higher and as such you'll be fuelling again without having to touch the throttle with your foot.
If you don't rev match then when you down shift your revs will be higher and as such you'll be fuelling again without having to touch the throttle with your foot.
This is not how modern fuel injected cars work. Fuel consumption is determined by the ECU and is directly proportional (but not linear) to the load required to fulfill the accelerator pedal or maintain idle RPM. When the wheels drive the engine, no fuel is consumed regardless of the RPM.
The only way there won't be an increased load on the powertrain is if the revs are matched. If the revs are mis-matched then the transmission will be at a different point in the powerband (likely out of the powerband) and will result in increased loads experienced.
Right. Perhaps jamesjguthrie isn't seeing the difference between engine noise (mechanical strain), and engine load. "Engine load" is the additional force requested, which will be negative when the wheels are driving the engine. He's also including rev matching in a conversation that is not about clutch or torque converter wear, so there's definitely some confusion.
I must be missing something here. Your revs will go up regardless due to the nature of downshifting. It's just a question of whether you get there immediately or if you slowly glide there at the expense of your clutch. It seems to me you'd actually use less fuel if you didn't rev match, since rev matching requires you to blip the throttle. That said, I'll take the throttle blip over the clutch wear any day.
