▁share ▁of ▁the ▁prof its ▁for ▁market ing ▁the ▁engine . ▁Among ▁the ▁license es ▁were ▁Da im ler - B enz ▁since ▁ 1 9 6 1 , ▁General ▁Mot ors ▁since ▁ 1 9 7 0 , ▁Toy ota ▁since ▁ 1 9 7 1 , ▁among ▁those ▁who ▁paid ▁higher ▁fe es ▁for ▁W ank el ▁R CE ▁rights ▁was ▁a ▁state - owned ▁engineering ▁firm ▁of ▁the ▁DDR . ▁Roy alt ies ▁for ▁the ▁W ank el ▁GmbH ▁for ▁lic ensure ▁were ▁ 4 0 %, ▁later ▁ 3 6 %. ▁ ▁In ▁ 1 9 7 1 ▁W ank el ▁sold ▁his ▁share ▁of ▁the ▁license ▁roy alt ies ▁for ▁ 5 0 ▁million ▁Deutsch marks ▁to ▁the ▁English ▁con gl omer ate ▁L on rho . ▁The ▁year ▁after ▁he ▁got ▁his ▁Techn ical ▁Development ▁Center ▁back ▁from ▁the ▁Fra un ho fer ▁Society . ▁ ▁From ▁ 1 9 8 6 ▁the ▁Felix ▁W ank el ▁Institute ▁co oper ated ▁with ▁Da im ler ▁Ben z ▁AG . ▁D - B ▁provided ▁the ▁operating ▁costs ▁in ▁return ▁for ▁the ▁research ▁rights . ▁ ▁He ▁sold ▁the ▁Institute ▁to ▁Da im ler ▁Ben z ▁for ▁ 1 0 0 ▁million ▁Mark s . ▁ ▁Personal ▁life ▁ ▁W ank el ▁married ▁Emma ▁" M i " ▁Kir in ▁in ▁ 1 9 3 6 . ▁Though ▁married ▁until ▁death , ▁they ▁had ▁no ▁children . ▁ ▁He ▁never ▁had ▁a ▁driver ' s ▁license , ▁because ▁he