Accelerating from 50mph. Which is the best gear 3rd or 4th?

[scoss]

Apologies if this a dull Sunday type question.
I thought about this the other day after overtaking a car along a country lane.
Assume I'm going at 50. In 3rd gear the revs are around 3200 ish. In 4th I'm just knocking on 2000 ish. Obviously I want to go beyond 70 so I'd change to 4th anyway. However would you intially drop to 3rd to use the remaining range of that gear before going into 4th? Or would you just stay in 4th from 50 at 2000?

Thanks

 

[RichardT]

It would depend how much room you have to overtake, and cosequently how fast you need to accelerate.

 

[scoss]

It would depend how much room you have to overtake, and cosequently how fast you need to accelerate.

Let's assume I need to accelerate as quick as possible. I'm finding 1st/2nd and 3rd around 2000 really responsive. Today 4th gear around 2000 didn't give me the same pull as the other gears.

 

[Flying Scotsman]

An auto transmission would drop down to the appropriate gear dependant on throttle input. If it was a manual transmission or auto transmission in manual mode, on a twisty country road I would drop down to 3rd gear.

 

[scoss]

An auto transmission would drop down to the appropriate gear dependant on throttle input. If it was a manual transmission or auto transmission in manual mode, on a twisty country road I would use 3rd gear.

Ok. I'm partly asking as I've been looking at the revo performance graphs. I'm gonna get more torque 2000 rather the 3200. So this is why I was questioning if the car would be quicker staying in 3rd @3200 or 4th @2000. I think to get the best from 4th i need to be nearer to 60.

 

[desertstorm]

I like to complete overtaking manouvres without changing gears if possible . I am assuming you have something like a manual TDI.
If you have to change when overtaking then that takes your hand off the wheel and your concentration slightly off the road. However 3rd to 4th is a quick change that you are unlikely to fluff, not like 2nd to 3rd possibly so it really depends on how quick you need to get around the vechicle you are overtaking.
You would complete the overtaking a lot quicker starting in 3rd than 4th.

 

[desertstorm]

You may have more torque but you are in a higher gear and the gearbox acts as a torque multiplier . The higher the gear the less that torque multiplier is.

 

[scoss]

I like to complete overtaking manouvres without changing gears if possible . I am assuming you have something like a manual TDI.
If you have to change when overtaking then that takes your hand off the wheel and your concentration slightly off the road. However 3rd to 4th is a quick change that you are unlikely to fluff, not like 2nd to 3rd possibly so it really depends on how quick you need to get around the vechicle you are overtaking.
You would complete the overtaking a lot quicker starting in 3rd than 4th.

Yeah I have a 150 TDI which has a stage 1. I'm still learning (obviously) on how to get the best out of the engine.

 

[Flying Scotsman]

Hmmm, knowing it is a 150 diesel.......Diesel engines lose a lot of get up and go at higher rpm levels...they really like the sweet spot of their torque range.

 

[scoss]

You may have more torque but you are in a higher gear and the gearbox acts as a torque multiplier . The higher the gear the less that torque multiplier is.

So then, is this why I'm feeling less torque at 2000 the future up the gear range I go?

Thanks for the info.

 

[scoss]

Hmmm, knowing it is a 150 diesel.......Diesel engines lose a lot of get up and go at higher rpm levels...they really like the sweet spot of their torque range.

Definitely so!

 

[KenL]

Whatever gear that gets you past in the shortest time.

You should not lose concentration when changing gear as that should be second nature.

 

[Joetidman]

In my S5 I'd say second! It goes up to 80mph before changing up, so very much depends on your engine and gearbox ratios. Also if you're in a petrol you want near max revs for max power whereas in a diesel you want 2/3's max revs


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[Forbzeeee]

Change down to 3rd and go to 4th when you're above 60mph

 

[lekky]

Interesting thread for me...! Knowing very little about how the internals of a car works...... Is it safe to hit max revs often? I have been tending to just follow the gear change indicator on the dash, but that tells me to change pretty early......

 

[Joetidman]

Interesting thread for me...! Knowing very little about how the internals of a car works...... Is it safe to hit max revs often? I have been tending to just follow the gear change indicator on the dash, but that tells me to change pretty early......

Its pretty hard to damage a car now days. Rev limiters mean that the engine is protected for the most part, although clearly staying at max revs with cold oil won't do you any favours. Once the oil is hot though, you should be fine. Dash indicator will be focused on economy not performance so you can safely ignore if you are driving enthusiastically!


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