Hi all!
Yesterday I was driving in my 2016 Mini Cooper S (~20K miles). Vehicle was in sport mode with automatic transmission in S mode(not D). So I pretty much accelerated while car was moving about 15/20 MPH, pressing the gas pedal pretty much all the way. The car showed S2, S3, S4, S5, S6, all while accelerating of course and past 100 - 110 mph, I noticed transmission went to S5 from S6 and car accelerated a bit faster than when it was on S6. I didn't move gas pedal or never took my foot off of it to make the transmission shift.

I just want to find out if this is the engineering design to make the car go faster at higher speeds?

 

Possibly. A number of car engines won't/can't pull as many RPMs in top gear (say 6th gear) as they can in the next lower gear (5th gear). While gearing is lower and the theoretical top speed is lower because of the gearing advantage the engine can rev higher and thus obtain a higher speed in 5th gear compared to 6th gear. So what you probably experienced was the engine controller detecting WOT or a torque demand greater than could be satisfied in 6th gear dropping the transmission down to 5th gear.

I wonder if my 2018 JCW will pull red line in 6th gear? Rhetoricial question as I'll probably never get a chance to try this. And based on how the car looks, I think its aerodynamics would come into play. As good as the car looks when I walk up to it or turn around to look at it after parking it, the JCW I suspect (at least based on looks) isn't that slippery.

 

Hmm, interesting...I remember when I had 2016 VW GTI (with performance package), it never did anything like this even in sport mode. GTI was pretty quick to 100, after that it slowly got to 110 and a bit slower to get to 120. The MINI goes up to at least 120 MPH a bit faster(after crossing 100MPH) than GTI did.

 

The limits of the aero will certainly show it's ugly face but my S with only a Dinan Elite was hitting just slightly under a buck-fifty on a very straight and deserted highway in Montana and certainly seemed to want to go faster if it weren't for the governor. I haven't had the cajones to try again after modding the car out though.