Mine had the HDi engine with DPF and 70hp.

Citroën were the first to make DPF standard.

Also, I would like to kindly remind you of the concept of "time". This was 25 year ago. The alternatives would have been worse. These days a C15 would be electric.

Obviously the OP is tounge-in-cheek, so keep it lightly.

But it does have merit: If you wish to measure your environmental footprint, you must look at the total lifetime of car, most importantly the manufacturing part. There is a difference between 900 KG of parts for a C15 vs 1,900 - 2400 KG for a Ford Ranger. These days most PM come from braking. Stopping 2000 KG will obviously cause more emissions from the brakes than stopping 1000 KG.

All in all, the point really is: The ratio between weight/size of the car itself and what is inside (people and/or server racks) has gotten completely out of hand. No, you do not need a 2,000 KG tank to move your 50-100 KG of flesh around. It's insanity, no matter if your care about the planet or not.