DIESEL TYCOON Trophy
You have used over 1000 l of diesel.
This will come naturally by dropping off crops and missions, harvesting, ploughing and sowing. When your tractors get to around 40l it is probably about time to go and fill them up at the petrol pump icon. I only had to fill my small harvester once and never had to re-fill my corn harvester. It will likely unlock early in your plat run. See Very Frequent Driver for boosting tips if you need them but it's highly unlike. Again, don't go for it early on - it will only make the grind for Pots of Gold and Harvest King harder.
Please note you need 1001, not 1000.