The local vehicle market is recovering from four straight years of decline which culminated in a 4% drop to 768,788 units in 2016 from a peak of 1.43m in 2012.
Economic growth has strengthened significantly this year, reflecting a pick-up in domestic consumption, investment and exports.
Third-quarter GDP growth came in at 4.3% year on year, up from 3.7% in the second quarter and 3.3% in the first quarter.
Toyota 's sales rebounded by 12% to 31,324 units in December after the company posted weaker sales in previous months while Isuzu 's sales declined slightly to 15,446 units, Honda sold 14,463 units (+39,8%); Mitsubishi 8,913 (+34.6%); Nissan 7,009 (+37.1%); and Ford 6,728 (+34.0%).
Sales of passenger cars jumped by over 40% to 41,449 units last month while SUV sales were up by close to 36% to 7,301, pickup trucks 50,459 (+8.4%) and other commercial vehicles 5,093 (-6.9%).
Total vehicle sales in 2017 increased 13.4% to 871,650 units.
Earlier in the month Mazda said it expected the Thai market to expand by 5.5% to 920,000 units in 2018 with its own sales amounting to 60,000.
Both Honda and the FTI are expecting more moderate growth – forecasting 900,000 units.