Power Reserve Meters

[mrmr96]

Some very high end cars (Bently, Rolls Royce type) have "Power Reserve" meters, measured in "%". What is the purpose of these? How does a driver make use of them? Are they to do with making the ride smoother for passengers somehow? Surely not just for gloating about the excess capacity of the engine?! haha! So, any ideas?

Cheers

[Slow]

Isnt it just a backwards rev counter?

[Bonefish Blues]

I have one of those too. I'm not sure it has quite the same cred. though...

[mrmr96]

Slow said:

Isnt it just a backwards rev counter?

No, power doesn't work like that. (E.g. at the same revs your power output depends on the throttle position. So at W.O.T. your power reserve will be zero, but your revs will change as the car accelerates.)

It's more like a backwards throttle meter (I think).

[poing]

mrmr96 said:

Some very high end cars (Bently, Rolls Royce type) have "Power Reserve" meters, measured in "%". What is the purpose of these? How does a driver make use of them? Are they to do with making the ride smoother for passengers somehow? Surely not just for gloating about the excess capacity of the engine?! haha! So, any ideas?

Cheers

My OCD doesn't like that gauge, why isn't it more symmetrical? Shoddy attention to detail.

[talksthetalk]

So basically it measures the distance between the accelerator pedal and the sheepskin rug?

[anonymous-user]

I want a car with just a speedo and fuel gauge... plus one red light for oil pressure/alternator.

[mrmr96]

talksthetalk said:

So basically it measures the distance between the accelerator pedal and the sheepskin rug?

Sort of, but I don't think power is linear to throttle (butterfly) position so it's also unlikely to be linear to throttle (pedal) position either.

[chris333]

yonex said:

I want a car with just a speedo and fuel gauge... plus one red light for oil pressure/alternator.

you want all the toys! Was it the original beetle where you had to stick a broomstick in the fuel tank to see how much was left?

[Pesty]

Isn't it something to do with the famous RR thing about not giving power outputs just that there is 'enough'

Thought thats how they came about but i may have dreamed that.

[Mastodon2]

So if you are pressing on and are about to make that big overtake, you can glance at the dial and decide how viable the overtake is, from doable to suicidal.

Just a bragging thing really, little practical use I'd imagine.

[zeduffman]

I suppose wafty Rollers are more about torque rather than outright power. They aren't designed to be revved until the pistons are making dents in the bonnet. Knowing that you're only using 3% of the available torque to cruise is more useful than knowing you're doing less than 2000rpm... Especially in an auto.

And there's the pomposity factor as well.

[RDMcG]

Its a subtle BMI indicator tied to a driver's seat weighing scale, reporting the number of pounds you can gain before being classified officially as powerfully built.

[cptsideways]

70mph in Ghost is about 6% iirc. I think you'll find the gauge is linked to injector duty cycle.

Trying to get one to read 100% for long enough to read it before loosing your licence, you would have to be quite brave, they are pretty rapid things if a "Wilton Prod" is required

Edited by cptsideways on Saturday 6th April 10:42

[Hereward]

cptsideways said:

"Wilton Prod"

I like that term, sounds like something out of the Viz Profanisaurus