We are often asked ... which Brompton gearing should I get?
Urban 2 speed C Line
Utility 3 speed C Line (discontinued in 2023)
Urban 4 speed P Line
Explore 6 speed C Line

so we tried to answer that scientifically in this video and failed

The video is split into sections:
0:00 | Intro
0:43 | Urban 2 speed test rides
1:48 | Utility 3 speed test rides
2:59 | P Line 4 speed test rides
3:56 | Explore 6 speed test rides
5:23 | Results analysis
8:08 | Outtakes

For the scientific answer we would recommend the Brompton gear calculator below:

http://xldev.co.uk/bgc.html

Which allows you to choose the gearing / tyre combination and shows how fast you will be going at 70 RPM (pedal RPM) in each gear

Bike details:
Urban 2 Speed 54T chainring 12/16T rear sprockets Kojak tyres
Utility 3 Speed 50T chainring 13T rear sprocket Marathon Racer tyres
P Line 4 Speed 50T chainring 4 rear sprockets Continental Contact Urban tyres
Explore 6 Speed 50T chainring 13/16T rear sprockets Marathon Racer tyres

Our sträva rides with the data are here we didn't post all the data as the details was getting too long!:

Brompton Urban 2 speed loop:
  / strava  

Brompton Urban 2 speed spin out test:
  / strava  

Brompton Utility 3 speed loop:
  / strava  

Brompton Utility 3 speed spin out test:
  / strava  

Brompton P line 4 speed loop:
  / strava  

Brompton P line 4 speed spin out test:
  / strava  

Brompton Explore 6 speed loop:
  / strava  

Brompton Explore 6 speed spin out test:
  / strava  

So in summary go try a handful of demo Bromptons and decide for yourself based on your personal riding style / preferences!