Sudden rpm drop at low speeds

[Bsmith]

I just noticed something today while in traffic. While cruising at low speeds of less than 40 mph taking my foot off the throttle has the rpms dropping almost instantly from 1800rpm to 1000 or even lower. Reapplying the throttle, even with a light touch has it jumping back to 1500-1800 rpm. 

Taking my foot off the throttle while crusing at greater than 40 mph and around 1500-2000rpm has the rpm holding as expected. No rpm jumping.

I dont think its gear ratio as in both situations im cruising with light throttle and not in 1st or 2nd or maybe 3rd. Im also not accelerating or on/off the brakes.

Anyone else notice this? Is this indicative of a transmission or other issue?

 

2010 rwd w/ 80k miles.

[sha4000]

I believe this is the normal behaviour of the 8 peed transmission. My 2007 does the same thing, jumps high on initial thrust and holds gears for longer after releasing pedal at higher speeds.