You may not understand either what it means to "lug" an engine or the reason for knock sensors.I disagree. Old school thinking about how cars were without knock sensors. "Lugging" these days is more a subjective term and relates more to performance than damage to the engine.
Knock sensors detect the vibration from detonation which occurs under conditions of pressure and temperature with low octane fuels. It also happens after normal spark ignition. Detonation is the result of several flame fronts colliding and producing a rapid uncontrolled burn that the engine cannot handle. High octane fuels are more resistant to producing the end products in advancing flame fronts which tend to auto ignite under the conditions mentioned producing the additional flame fronts.
As far as lugging is concerned - it occurs when the engine is operating at too low an rpm level for its ability to deal with the torque required for acceleration at wide throttle openings. That kind of situation can easily occur in high gears and low rpms when climbing hills. Under these conditions the oil pump may not be circulating oil fast enough or with enough pressure to protect the plain bearings in the crank journals. Too much pressure is being placed on these bearings and connecting rods for safe operation of the motor. You can hear the mechanical sound when this happens. Don't confuse mechanical knock with spark knock.
This situation is particularly critical with a three cylinder engine.
If the car won't accelerate or accelerates very slowly at wide open throttle, then you are in too high a gear - and that can easily happen in 5th gear under 50 mph with the smart.
Actually they are not "fine". The computer programming is designed for maximum fuel mileage but is not suitable for drivability. The rationale behind the ultra low rpm gear shifting is that maximum fuel mileage is obtained at wide throttle openings and low engine speeds. This is a marketing decision, not a practical or drivability decision and is not designed for engine longevity either.The shift arrows are fine for normal driving on level roads with average acceleration. They will improve MPGs.
I'm absolutely in agreement with that statement.The transmission is for good reason the number one complaint of nearly every reviewer. It sucks. When someone comes out with a similarly sized car with a better transmission the smart will lose sales quickly. (Toyota iQ). In this day and age it shouldn't take elaborate instructions on how to shift to make a car smooth and enjoyable to the average driver.
I don't recall telling you that.Before you tell me I don't know how to shift or drive a manual, I'll just say, you're wrong.
The manual shift in the smart is not a normal manual shift. It does take some experience and perhaps advice to obtain the smoothest shifts since some of the operations are computer controlled and they have to be reacted to in specific ways that are not issues with normal manual transmissions. Drivers accustomed to normal manual shifting will still take some practice with this transmission to obtain the smoothest shifts from it.
If this was a dual clutch automated manual this discussion would not have to take place.