Engine braking going down steep hill

[Richolf]

Hi

i may have missed this in the manual.  The current Rx450 doesn’t have a B for engine breaking or a low gear/being a cvt so what is the recommended way to drive down very steep hills ?

thanks 

[Barry14UK]

Slowly?

[dublet]

If in doubt - flat out.

[Herbie]

2 hours ago, Richolf said:

Hi

i may have missed this in the manual.  The current Rx450 doesn’t have a B for engine breaking or a low gear/being a cvt so what is the recommended way to drive down very steep hills ?

thanks 

Just apply gentle brakes and the regen system will charge the traction Battery to full quite quickly. Once the Battery can accept no more charge the hybrid system will then use MG1 to spin the engine but without fuel or spark, so that it just becomes a big load for the motor to turn to use up the excess electricity. I suppose you can think of it as 'engine braking on steroids'.

[flookyk]

9 hours ago, Richolf said:

Hi

i may have missed this in the manual.  The current Rx450 doesn’t have a B for engine breaking or a low gear/being a cvt so what is the recommended way to drive down very steep hills ?

thanks 

Put the gear selector into manual (right) and manually select a lower gear 3 or 2 as required.. this also works in winter to keep your speed down slow to a crawl if required downhill to keep control.

Even though its  CVT these "false" gears give you the engine braking you are looking for.

[Richolf]

Thanks exactly what I was after

[Mihanicos]

Whenever you drive in any gear and you do not press the accelerator, there is engine braking by using the electric motors to generate electricity. 

The lower the gear you select the higher the braking. This is possible until the batteries become fully charged. At this point you will feel the loss of engine braking and the car will then accelerate due to gravity if you are going down hill, depending on the gradient. To continue braking you engage B which is a resistor so that the generated electrical energy is dissipated as heat.

Chris.

[flookyk]

3 hours ago, Mihanicos said:

Whenever you drive in any gear and you do not press the accelerator, there is engine braking by using the electric motors to generate electricity. 

The lower the gear you select the higher the braking. This is possible until the batteries become fully charged. At this point you will feel the loss of engine braking and the car will then accelerate due to gravity if you are going down hill, depending on the gradient. To continue braking you engage B which is a resistor so that the generated electrical energy is dissipated as heat.

Chris.

The Gen3 and Gen4 RX450h does not have a B setting.

[m4rkw]

Similar question on mine - I have a simple non-hybrid with a 4-speed transmission. Lots of steep hills in Scotland. I've been using 2nd to descend where there are corners (except for the long straight going south on Lecht road - that one I just let it roll and pretend it's a rollercoaster for cars). 1st would give more engine braking but it makes me a little nervous given that it revs up to nearly 5000rpm, not sure if that's good for the engine.

Also remember to use the brakes intermittently, if you keep them on all the way down a long steep hill you can overheat them and cause damage.