Only one filling station is available in the thanamalwila town. Good service is available here. If you go to embilipitiya, filling station is available at embilipitiya 40 km distance. If you go to udawalawa, filling station is available at udawalawa 40 km distance. If you go to wellawaya , filling station is available at thelulla 25 km distance. If you go to weerawila or tissa, katharagama , filling station is available at lunugamwehera 20 km distance.
Its the only filling station you find after Ambilipitiya when you are traveling via Udawalawa. If you are going towards Katharagama, the next gas station you find is more than 25km away. Its in Katharagama, don't miss if you are running out of fuel. And remember, this one opens at 8am. Not before that. That's a bad experience for early travelers.
Good! :-)