Change of gear

Go! Drive and Camp Camp Guide - - Front Page -

First gear is for pulling away, but should you tow in fifth?

You don’t need to be a me­chan­i­cal eni­neer to un­der­stand that you should shift the gears as smoothly as pos­si­ble while ac­celler­at­ing to cruis­ing speed. Keep in mind that Lewis Hamil­ton’s fuel is spon­sored. Driv­ing like him may per­haps clas­sify you as a good driver, but it will never be eco­nom­i­cal.

So it’s im­por­tant to know how high your en­gine can rev be­fore you shift gears in or­der not to dam­age the gear­box. This is where do­ing your home­work comes in.

Take a diesel en­gine of which the op­ti­mal torque, for ar­gu­ment’s sake, is reached at 1 900. The top 20% of the torque curve will there­fore be be­tween 1 520 r.p.m and 2 280 r.p.m. You there­fore have to pad­dle that gear lever like a row boat to keep the revs within th­ese pa­ram­e­ters.

When the revs drop as low as 1 520 r.p.m, it’s time to shift down and when they reach 2 280 r.p.m, you must se­lect a higher gear. Con­tinue like this un­til you reach the de­sired speed – re­gard­less of which gear you are in.

Head­wind. When tow­ing, aim to keep your ve­hi­cle’s revs in the up­per 20% of its torque curve. In this case, be­tween 1 520 r.p.m and 2 280 r.p.m.

Just right. Aim higher. Aim lower. If the spec­i­fi­ca­tions on your ve­hi­cle state that op­ti­mal torque is pro­duced at 1 900 r.p.m, this is where you get the best power. When the rev counter drops to be­low 20% of the curve, it’s time to se­lect a lower...

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