The Class 165 and 166 DMUs were introduced in 1990 for local and regional services on the Thames Valley and Chiltern routes. Many have now moved to other GWR services further west. As DMUs go they're among the most attractive in use today with rounded fronts unspoilt by corridor connections.
- Class 150
- Class 156
- Class 158, 159
- Class 168 & 170-172
- Class 180
- Class 185
- Class 220, 221, 222
- Class 319, 769
- Class 320, 321, 322
- Class 325
- Class 345
- Class 350
- Class 375, 377, 379, 387
- Class 390
- Class 397
- Class 421 4-CIG
- Class 423 4-VEP
- Class 442
- Class 444, 450
- Class 455, 456
- Class 458
- Class 491 4TC
- Class 701
- Class 707
- Class 800 - 810