Tiny new en­gines, big power

Ford and Toy­ota’s lat­est blocks push the lim­its of fru­gal fuel use

The Witness - Wheels - - MOTORING - ALWYN VILJOEN

FORD and Toy­ota have an­nounced smaller en­gines with power fig­ures associated with much big­ger en­gines just a few years ago.

Ford’s EcoBoost range of small turbo en­gines fea­ture in ev­ery­thing from Fi­esta to the F-150 bakkie.

The small­est EcoBoost engine is now get­ting smaller, thanks to cylin­der de­ac­ti­va­tion.

Toy­ota has mean­while un­veiled its Toy­ota New Global Ar­chi­tec­ture (TNGA) en­gines that will be used in both petrol and elec­tric hy­brid ve­hi­cles later this year.

Ford’s two power

Cylin­der de­ac­ti­va­tion is not a new idea, dat­ing back to 1981 and more re­cently ap­plied by Jeep in the Chero­kee.

But Ford will be the first to cut fuel to a cylin­der in a three-cylin­der engine. Their sys­tem only cuts the cylin­der when the Ecoboost is run­ning un­der light loads to make the al­ready ef­fi­cient engine a hy­per-ef­fi­cient two-cylin­der on the high­way or while idling.

To get the idling cylin­der pump­ing again takes just 40 mil­lisec­onds, and the sys­tem can kick in at engine speeds up to 4 500 rpm. A new sin­gle-piece camshaft makes room for the ex­tra oil chan­nels and valve shift­ing com­po­nents needed to make cylin­der de­ac­ti­va­tion work. A new camshaft chain and valve rock­ers have also been fit­ted to han­dle the me­chan­i­cal strain associated with cylin­der de­ac­ti­va­tion.

De­nis Gor­man, pow­er­train en­gi­neer at Ford Europe, said, “Our re­search shows that in most driv­ing sce­nar­ios the sys­tem will be ac­tive for just a few sec­onds at a time, mak­ing fast and seam­less op­er­a­tion cru­cial, and has the po­ten­tial to im­prove fuel ef­fi­ciency by up to six per­cent.”

Toy­ota’s sav­ings

Toy­ota will in­tro­duce 17 ver­sions of nine new en­gines and 10 ver­sions of four trans­mis­sions from 2017 to 2021.

The new en­gines are called “Dy­namic Force En­gines” and com­bine loss re­duc­tion (lower en­ergy losses), im­proved fuel com­bus­tion, and im­proved air in­take ef­fi­ciency.

The first engine in this new ar­chi­tec­ture is a 2,5-litre four-cylin­der that achieves 40% ther­mal ef­fi­ciency as a petrol-only engine, and 41% when used in a hy­brid sys­tem.

To go with the new TNGA en­gines, Toy­ota has also de­vel­oped new trans­mis­sions.

A new eight-speed au­to­matic and a new 10-speed au­to­matic (8AT and 10AT) are be­ing in­tro­duced. Im­prove­ments in gear tooth sur­faces and clutch ma­te­ri­als re­duce fric­tion through­out the trans­mis­sions.

Newspapers in English

Newspapers from South Africa

© PressReader. All rights reserved.