P E H
I agree with your comparisons of the SD and SDL accelerations. I do not detect any significant difference in the amount of pressure needed to depress the accelerator, but there is a definite difference in the response of both at similar positions. My SD is quicker on initial acceleration where the SDL after 2500 rpm really starts to pull. I drive both of them regularly. I just accepted it as the way they were designed, perhaps they have different rear gear ratios, the SD gets about 5% better fuel economy.
Tom
82 SD
86SDL