Diesel Driving

[Robdrums]

Hi all,

Just wanted some input on how everyone drives their diesels (I'm driving a 150 Leon FR), as it's my first one.

For normal, econommical driving I change up at about 2-2500 rpm and try to go along at about 1500 (is this too low, is it bad for an engine to be labouring if I drop speed, say 30mph in fourth?). I've been told it has more torque at lower revs so you'll get quicker acceleration. But it seems to be a quicker route to higher speeds if you boot it up to 3500, maybe even 4000rpm (mainly second or third, not first or fourth onwards), say accelerating down a sliproad or something off a roundabout.

3rd at 3500 takes me up to about 60, do you think that's quicker than 4th at about 40 or 50mph? Or would it be just as well from there, assuming I'll be going no higher than 90, to change straight into fifth, or even sixth?

It seems that, whether there is greater torque at lower revs, the trick is for the turbo to still be engaged after each gearchange. That is, if you change up at 2500rpm, the revs drop to about 1500, therefore causing a lag before the turbo pulls you up, whereas if revs drop to 2000, it's already boosting straight away.


Secondly, motorway driving, do you ever drop into fifth or even fourth to overtake at 70mph? It pulls well still, but the 70-100 sprint isn't any better in fifth it seems, and fourth is just way to much. Or is it? I remember the Golf GTi feeling quicker 70-100, but that might just be complacency on my part now as I drove a 1.1 Metro when I drove the Golf.

Thanks in advance for any input.

Rob

 

[craig-pd130]

The 150s rev a bit more freely than the 130s, with the downside of a bit more lag lower down, so for normal economy driving keep it on the torque plateau between 2 & 3K rpm.

I don't what the gear / speeds are for the 150FR but if you aim to keep revs above about 17 / 1800 in third gear or above then you won't be labouring the engine and will have instant go

I will sometimes use 5th at 70-ish but 6th usually does the job. If you used a stopwatch you'll probably find you're leaving the GTi for dead 70-100 in 5th

 

[Triple D]

Driving in to low a gear and then booting it wont do any harm when in standard form, but if you had it remapped then eventuslly you might get clutch slip if you do it regular.
But also, you need to think that if you drive in to high a gear at low rpm e.g. 1k rpm and try to accelerate, the amount of vibration going through the gear box and engine shaft into the DMF and clutch will be pretty high. You dont feel it as much in the car because the damping springs are absorbing it, but you will here the car starting to struggle. We have just had a DMF back in work through warranty that is completly fooked, all the grease has come out from inside it and i think the damping springs inside are fooked aswell. Aparently this may have been caused by high gear driving techniques.Just a little bit of an insight into the work a DMF does and what the car is going through at low rpm when accelerating.

 

[Robdrums]

I also find it hard to judge whether to shift down to overtake like you would do in a petrol car. Say, trundling in 4th at 40, shifting down to third doesn't seem to make much difference, or rather, it does, but then it seems to want fourth again (if you're not taking it up past 50 or so).

I find it interesting that you say you'd be better of dropping to fifth for motorway overtaking, say pulling out at 70 and taking it up to 90 or so. Though it's perfectly capable in sixth, it'll be cruising by that time at about 1800 revs, so you won't see the turbo til about 90mph it seems. But saying that, when I accelerate as described in third up to about 60mph, I'll be at 80 by the time fifth is even an option, so it must be really.

Cheers

Rob

 

[redcupratdi]

just drive it when the engine sounds like it its labouring high or low revs change gear!

u can drive it forexample
accelerating:
2-3000 revs
1500-2500 revs
or mine 2500-4500 revs!

make sure you give it a whole rev range on each jorney example 2000-4000 in 3rd clear the pipes!

cruise between 1500-2500
drop a cog when overtaking if below 1900 rpm,

try not to redline as when changing gear power drop for a second change just before or after 4000 when blasting around.

for nice torquie aceleration change at 3200 the torque pulls you along without any problems weird feeling!

just drive how you feel it a good versitile engine and can be drivin in lots of diffrent sytles just a matter of habit and you will find the sweet spots shifting

my favourite is tcs off 2nd gear at 30 rev drop clutch and you skid up the road to about 55 change to 3rd goodbye! leaving other cars in your wake!

don't labour engine don't keep above 3000 for long priods no reason to do it also below 1500 you have 6 gears to use no excuse for a labouring engine
hope this helps
james

 

[redcupratdi]

on the motorway yes i do drop it into 5th or fourth to other take but 5th is prob the best to do it at changge up as soon as passed or 3900rpm

 

[micky 32]

This is my best acceleration for my state of tune. 2nd gear 50mph, third gear up to 80mph, 4th on to 100 and then 5th and so on.

 

[sssstew]

The 150s rev a bit more freely than the 130s, with the downside of a bit more lag lower down, so for normal economy driving keep it on the torque plateau between 2 & 3K rpm.

I don't what the gear / speeds are for the 150FR but if you aim to keep revs above about 17 / 1800 in third gear or above then you won't be labouring the engine and will have instant go

I will sometimes use 5th at 70-ish but 6th usually does the job. If you used a stopwatch you'll probably find you're leaving the GTi for dead 70-100 in 5th

yep agreed with that style of driving.

 

[Robdrums]

Nice one, thanks for the responses everyone, I'll keep on experimenting. At least I don't need to worry about over-revving as much as I thought as I did, some people will tell you anything over 3000rpm in a diesel is not only bad for it, but pointless anyway due to the low down torque. I had a feeling that the 150 might be more tuned like that, hence the sometimes uninspiring lag at lower revs.

I've yet to experiment with taking the TCS off actually, maybe that could be fun (though maybe wait til it's dry)

Cheers

Rob

 

[prc]

Power on the tdi starts falling off above 4000 and not 3000rpm (stock and with most maps), so it's starts being pointless reving much above 4000rpm.
try not flooring it in a high gear (>4th) at such a low rpm as mentioned 1600rpm. Doing this will tend to cause big overboosts from the turbo and all the torque will start putting some wear and tear on the DMF (even in stock).

BTW--Enjoy the TDI..

 

[sssstew]

yep thats right rob dont worry at all about overrevving, diesels cope very well indeed with being driven hard.

 

[Kam]

just drive it when the engine sounds like it its labouring high or low revs change gear!

u can drive it forexample
accelerating:
2-3000 revs
1500-2500 revs
or mine 2500-4500 revs!

make sure you give it a whole rev range on each jorney example 2000-4000 in 3rd clear the pipes!

cruise between 1500-2500
drop a cog when overtaking if below 1900 rpm,

try not to redline as when changing gear power drop for a second change just before or after 4000 when blasting around.

for nice torquie aceleration change at 3200 the torque pulls you along without any problems weird feeling!

just drive how you feel it a good versitile engine and can be drivin in lots of diffrent sytles just a matter of habit and you will find the sweet spots shifting

my favourite is tcs off 2nd gear at 30 rev drop clutch and you skid up the road to about 55 change to 3rd goodbye! leaving other cars in your wake!

don't labour engine don't keep above 3000 for long priods no reason to do it also below 1500 you have 6 gears to use no excuse for a labouring engine
hope this helps
james

I agree whole-heartedly with this. When I first bought my diesel, I used to have a habit of keeping the revs low. Now, I just drive it as I would a petrol car. Using the rev range depending on the traffic, cruise around 2k revs, normally changing between 2.5 - 3K revs. I never go near the red line though.

 

[red line fun]

i 'just drive it' if you see what i mean, this is my first diesel as well but it's no different in that the car tells you when it needs to change gear, labouring ain't great for any car petrol or diesel.

as for motorway driving, from 70 up i'm in 6th. even for overtaking as it's quick enough for me.