How to drive a Mondeo TDi? Stupid, I know.

[CAH]

Hi Peeps,
Bought a 2002 2.0 TDI yesterday and it's the first time I've had a disesel. At this risk of making it seem like I'm a complete idiot, I need to ask a potentially stupid question.....

having never had a diesel before, never mind a TDi, I must admit that I am loving it. However, is there a knack to it? Sometimes I seem to have WAY too much power - generally when I'm going round a roundabout or pulling off from a junction. More worryingly is the fact that on two occaisions, when I've gone to overtake something, the turbo seems to have disowned me competely and I have bugger all power in 2nd but if I change to 3rd I can get it back. Top end speed isn't an issue, and in a straight line without any slow lorries in front of me it's pretty damn quick. It just seems to be a problem when I've overtaking.

I wasn't too concerned yesterday when I overtook a lorry in slow-mo as there wasn't anything else coming, however today was bordering on needing a change of underwear.

What am I doing wrong?? Or are all TDi's this temperamental? Or should I just get used to being religious every time I overtake something? Maybe I should practice by overtaking everything on the way to work tomorrow??

And I'm fully expecting the silly comments about women drivers and no I'm not blonde.

Thanks peeps

[mrmr96]

Being _very_ general diesels have more torque than petrol engines, but less power. What this means for you as a driver is that in a diesel there's more 'accelerating grunt' at lower revs (like 2000-4000) than there is at higher revs (4000-6000). So it may feel a bit 'gut less' at the top of 2nd gear and have more 'pull' if you change up into 3rd. Petrol engines are, in general, the opposite, with torque being higher up the revs, so revving it gives you more 'grunt' in a petrol.

(I could start posting pictures of power and torque curves, but I'm trying to tailor my answer into terms that will be useful to you as a driver.)

Hope that helps.

[CAH]

So basically, instead of trying to overtake something at the top of 2nd before I change, I should be at the bottom end of 3rd to get the most ooomph out of it?

[nelly1]

Don't forget that the engine has a torque truncation map in first and second to protect the gearbox.

You don't get full fuelling (and hence torque) until third gear (unless you've had a re-map )

[CAH]

A friend has suggested a re-map......I resisted the temptation to point out that I owned a sat-nav

I shall practice overtaking when I next drive to work and see if I can get the hang of it without killing myself.

Thanks for the speedy replies folks.

[mrmr96]

CAH said:

So basically, instead of trying to overtake something at the top of 2nd before I change, I should be at the bottom end of 3rd to get the most ooomph out of it?

Pretty much.

A good way to learn where your car delivers the power would be to put it in 3rd or 4th gear at low revs (low speed) and accelerate all the way through the rev range to the top. (Make sure the car's been running for a couple of miles prior to doing this to avoid damage.) Do it coming off a roundabout onto a dual carriageway or something.

You'll feel not a low to start with (below about 2,000rpm) then it will build into a big shove in the middle and tail off at the top. Try not to watch the rev counter too much while you do this, I don't want you to crash, but if you can glance down when the shove is strongest, that's where the max torque is. And if you glance down again when it starts to fall away then you know at what point you probably want to consider changing up the gears.

Does that make sense?

[mrmr96]

CAH said:

I shall practice overtaking when I next drive to work

Seems we were posting at the same time.

As I suggested, driving through the whole rev range in one gear will help you learn where the power and torque are on your car. Once you get the hang of leaving it in one gear try coming off the roundabout and then changing up just as the torque starts to drop off, you should find you're able to maintain pretty strong acceleration.

This is bit like 'practicing overtaking' except you get to do it on a dual carriageway without the danger of a head-on if you misjudge something whilst learning.

[CAH]

Thanks very much - I'm next driving to work on Thursday, so will report back Thursday evening, assuming of course I survive the trip
(If you live near the Derby/Notts area, it might be an idea to stay away from the A38 on Thursday just in case I get it wrong)

[Simbu]

If you're feeling particularly pedantic about your diseasel driving you can do what i do in mine, which is to keep off the turbo until the engine's warm and to keep off it for the last 1/2 mile of my journey if i can (or leave the engine to idle for a minute when you stop). This typically reduces wear on the turbo and associated gubbins. The turbo on your car will kick in around 1900rpm i expect(you'll hear a subtle whine building up to that point and beyond as the turbine spools up if you listen carefully).

[0pposite_Lock]

One more thing, torque is limited in 1st and 2nd gears on the TDCi engines as a means of protecting the drivetrain so its no surprise it feels quicker in 3rd The transient over boost function also becomes active from 3rd gear +

[nelly1]

0pposite_Lock said:

One more thing, torque is limited in 1st and 2nd gears on the TDCi engines as a means of protecting the drivetrain so its no surprise it feels quicker in 3rd The transient over boost function also becomes active from 3rd gear +

<Ahem!>

Seven posts up...

/<Ahem!>

ETA - learn to count properly...

Edited by nelly1 on Sunday 12th September 22:13

[CAH]

Hi all
Successfully managed to overtake on the way home from work without killing myself
Also dropped in at the garage over the weekend for my mechanic to have a quick squizz and check it over. He took it out for a quick run and declared that it "goes like f-ing stink!" and thought it was the 2.2 version, not the 2.0.
I have to say, I know I've only had it a week but I have fallen in love with it

[4mo]

I have to think which car I'm in when it comes to overtaking, Passat (petrol) drop a gear and launch generally changing back up way after passing, Alfa (diesel) ensure revs are about 2k and boot it. Do it wrong in the Alfa and your on the rev limiter before your even along side the car your trying to over take.