▁" P 5 B " ▁model ▁name ▁came ▁from ▁Bu ick , ▁the ▁engine ' s ▁origin ator . ▁R over ▁did ▁not ▁have ▁the ▁budget ▁to ▁develop ▁a ▁new ▁engine , ▁hence ▁they ▁chose ▁to ▁re develop ▁the ▁light weight ▁al umin ium ▁engine ▁available ▁from ▁Bu ick . ▁They ▁made ▁it ▁consider ably ▁stronger , ▁which ▁added ▁some ▁weight ▁but ▁still ▁maintained ▁the ▁engine ' s ▁light ▁and ▁compact ▁features . ▁The ▁Borg ▁Warner ▁Type - 3 5 ▁automatic ▁transmission , ▁hydro ste er ▁variable ▁ratio ▁power ▁ste ering ▁and ▁front ▁Lucas ▁fog ▁lights ▁were ▁now ▁standard . ▁ ▁Output ▁of ▁ ▁was ▁claimed ▁along ▁with ▁improved ▁tor que . ▁When ▁introduced ▁in ▁ 1 9 6 7 ▁the ▁Bu ick ▁designed ▁V 8 ▁produced ▁ ▁at ▁ 5 , 2 0 0   r pm ▁and ▁ ▁of ▁tor que ▁at ▁ 2 , 6 0 0   r pm , ▁the ▁new ▁engine ▁provided ▁improved ▁performance ▁and ▁fuel ▁economy ▁resulting ▁both ▁from ▁the ▁greater ▁power ▁and ▁the ▁lower ▁weight ▁of ▁the ▁power ▁unit . ▁ ▁The ▁exterior ▁was ▁mostly ▁un changed , ▁apart ▁from ▁bold ▁' 3 . 5 ▁Lit re ' ▁bad ging , ▁a ▁pair ▁of ▁fog ▁lights ▁which ▁were ▁added ▁below ▁the ▁head ▁lights , ▁creating ▁a ▁striking ▁ 4 ▁light ▁array , ▁and ▁the ▁fitting ▁of ▁chrome ▁Rost yle ▁whe els ▁with ▁black ▁painted ▁inser ts . ▁The ▁P 5 B ▁existed ▁as ▁both ▁the ▁ 4 - door ▁coup é ▁and ▁sal oon ▁body