I agree that shutting down and engine on taxi in does require some forethought. If you have to make a sharp turn to get into the parking spot or onto the gate then maybe you should consider which (if any) engine to shutdown. This is all part of the decision making processes that we are paid for. We all make bad decisions but to deny this valuable cost saving measure because of a few isolated incidents is silly.
At our company there has been extensive research performed on both the cost issue and the pros and cons of single engine taxiing. We operate a fleet of 23 B737-200s with approximately 1000 departures a week on a mainly shorthaul domestic operation.
The numbers given to us were similar to the following. If we could save 150 lbs of fuel on 50% of our departures, which is not unreasonable, the fuel savings alone over a 12 month period were in excess of 1 million dollars. This is nothing to turn your nose up at.
I have spoken to our maintenance folks and they have stated that they have not noticed any problems with nose wheel scrubbing or excessive engine wear and tear due to single engine taxiing.
We have guidelines in place some of which include recommended maximum N1 settings and recommended maximum weights for single engine taxi. We are also prohibited from single engine taxiing on contaminated or slippery ramps and taxiways.
As always you should follow your company's SOP and recommendations. I am just providing my point of view.
Cheers
