SELECT engine FROM table_name_1 WHERE tyres = "g" AND chassis = "d3 d4" AND driver = "jan lammers" AND rounds = "4-6"
Mesin apa yang digunakan selama balapan yang didorong oleh Jan Lammers menggunakan sasis D3 D4, membuat ban G dan putaran 4-6?
CREATE TABLE table_name_1 (engine VARCHAR, rounds VARCHAR, driver VARCHAR, tyres VARCHAR, chassis VARCHAR)