We are seeing 15-20% better fuel economy between rhe "old" Suzuki 115and 140's nd the new "a" series just released. Several friends have recently upgraded to the new model and are amazed at the difference.
While the basic engine remains the same, under the cowl, you would barely recognise them as the same engine. Completely new exhaust and EFI systems, intakes, just about everything. Quieter, smoother, much better acceleration, and less emissions as well.