There are probably dozens of posts on the subject of the transmission and shifting. After feeling confused-informed-confused-etc, I decided that the computer is performing all of the shifting functions and when I let up on the accelerator while it is performing a shift, I'm confusing it. I've been driving and letting the car shift and it seems fine.
I think one reason this is so noticeable for Smart drivers is that if you are accustomed to driving a manual transmission, you are idle during the shifting when you had been doing the whole gas-clutch-shift-gas process where you let up on the accelerator as you are putting in the clutch and shifting gears, then starting to accelerate as you let out the clutch in the new gear. Now you're sitting quietly while the car does all of that.
The car being optimised for fuel efficiency, it does tend to do things that you might do differently because it wants to keep fuel consumption down. Like that advice about accelerating like there's a raw egg between your foot and the pedal. Even if we're taking it easy, we're probably more heavy-footed than the Smart computer and it has the last say on how much gas it feeds the engine.
I have also seen instances where the process of shifting up is interrupted by an incline in the road where the engine has to pull more and it begins to shift back down before it has (or seems to have) completed the upshift. I have a gentle hill near home where this occurs and now I switch to manual and keep the car in the lower gear as I'm going uphill and shift near the top.
That's the joy of having the options the Smart offers. Your driving style changes as you spend more time with the car and you find ways to get more out of it.
Linear Mode
