Gear shifting with diesel

[en13]

wow. i have to write this down! i've always been in the habit of clutching in, i think it's because i have this mindset that if i slow down at say 4th gear without clutching in/changing the gears, the car will stall...

yeah i'm still running the car in- it hasn't even done 100! but i'll keep all this in mind when it is run in.

For slowing down I would be leaving the car in gear with the clutch out, changing down gears as I go. Aim for being in a gear that you could accelerate in if you had to (ie keeping the revs above 1400 or so after you have let the clutch out). Someday this habit may just save your life if you ever need to get out of someone's way.

If I am driving up a steep hill I would be keeping the revs above 2000. Just because a TDI will pull up a steep hill at 1400 or 1600 rpm doesn't mean it is good for the engine to do so.

If driving on the flat or downhill it is acceptable to run at low revs (unless you are still trying to run the engine in).

I am happy to use full throttle on a warm engine and regularly run it up to 3500 right from the very beginning (ie less than 100Km on the odometer), and up to 4000rpm once the car has done 1000Km.

I am firmly of the opinion that the best way to run an engine in is by allowing it to work, but there are many and varied opinions on the best way to run engines in (particularly diesels). Try a search on this and other VW forums and you'll see what I mean.

and thanks for that mischa, i didn't know that just revving the engine won't seal my rings- it just seems like everyone refers to it as that. thing is, i can't even get by 3000 without shuddering and thinking the engine's going to die!!! by revving up to about 3000, i can actually use 2nd gear to 55-60km/h! is that what everyone else gets?

simply revving the engine isnt going to seal your rings. you have to use hard acceleration to do so. so accelerate hard to the speed limit whenever you can but try not to go above 3800 revs in the first 1000kms.

[Logzy]

I kept my revs below 2500rpm. Bazza

Why....???

[gregozedobe]

Thing is, i can't even get by 3000 without shuddering and thinking the engine's going to die!!! by revving up to about 3000, i can actually use 2nd gear to 55-60km/h! is that what everyone else gets?

Speed in gears depends on the ratios in the gearbox and final drive. As long as your engine is properly warm, revving it to 3,000rpm under load (or even better, 3,500 ) won't do it any harm at all, and in fact will do it a lot of good.

You may just need to get used to the noises a diesel makes if you haven't driven one very much (they are different and noisier than petrol engines).

When cruising on the freeway or highway try to vary your revs between 1800 and 2,500 when running it in (we aren't telling you to drive along with your engine constantly revving at 3,500rpm), with short bursts of hard acceleration to 3,500 when traffic permits (eg after 60Kmh limits, roadworks etc).

[en13]

yeah i think i just have to get used to the noise it makes and i just have to get over my baby style of driving thanks everyone!

[mikinoz]

Like those before, I feel that keeping the car in gear is best.

You will end up with a greater particulate buildup if you coast to a stop in neutral, than if you don't and this will cause more soot at take off.

I hope you enjoy it!

[en13]

omg you are like the king.

hahah i might change my mechanic after what you've said!

i had absolutely no idea about not running the tank down, THANKS! i refuel when the light flashes and i was actually toying with the idea that i should just all the way down to 0, cos that's what i did with my previous car. but now that i know.... geez.

now here's another dumb question from me- please define engine breaking. wiki says that it means clutch down. no one else says this. what i've thought is engine braking is- clutch down, press brakes, slow release clutch.
am i correct?

we really need a forum for manual drivers who have driven auto cars for too long...

The notion that a diesel engined car should be driven like a petrol-fuelled otto engined car is bad advice. Change your mechanic immediately!

And that means that for a driver in a TDI, you should only use the footbrake for fools, red lights, and authority figures (who may or may not be fools). Instead, a TDI driver should use engine braking to slow the vehicle down (and touch the brake pedal so the red lights at the rear glow).


4. Fuel
Put those two together and operators of diesel engines should avoid letting the fuel tank get below 1/3 full. The fuel tank accepts heated fuel returned from the injectors. If the fuel quantity in the tank is low, then the average temperature of the fuel in the tank gets higher.

That means you should avoid the practice that some petrol engine drivers have of running the fuel tank close to empty. If you want to keep fuel consumption records, do it using the MFD reading or (even more accurate) keep a log of distance travelled and fuel supplied - and don't talk about kilometres per tank.

Keeping the fuel tank full or fairly full with a diesel does not run the risk of leaks from the fuel filler cap, due to fuel expansion on a hot day, that a petrol vehicle does. Keeping the fuel tank full is a good practice because it diminishes the chances of water condensing in the tank because of overnight cooling.

Note that diesel fuel has traditionally not been treated as cleanly in the refinery-wholesale distributor-retailer pipeline as petrol has. That means the chance that you buy diesel fuel that is dirty and/or may contain water is higher than for buyers of petrol. Note also that diesel fuel (and petrol) is made to be used in a few months - it does not have a long shelf life.

That means that you should patronise fuel retailers that have clean underground tanks and have a good turnover of fuel (ie they sell a lot of diesel fuel). In addition, some brands of diesel fuel (including BP) have a reputation for being cleaner and more carefully blended than others. BP led the way in Australia to lower sulfur diesel fuel (and are continuing to lead the way to even lower sulfur fuel, depending on where you live - check the BP website). BP is also one of the few refiners/retailers to state transparently on their website the cetane rating, lubricity etc of their fuel.

Cheers

[en13]

Engine braking is using the engine to slow the vehicle down. That means right foot off the throttle, left foot off the clutch. The instantaneous fuel consumption on a TDI read 0.0 L/100 km. In other words, slow down *in gear*.

ohhhh... so basically I'm have to let the car slow down without pressing on anything. wouldn't it stall!?

If you need to increase the rate of deceleration, change down a gear (ie from 5 to 4, 4 to 3, 3 to 2). And get the left foot off the clutch pedal.

After changing down a gear, you may need to increase the engine speed as you let out the clutch, to match the speed of engine to the speed of the road wheels. That doesn't necessarily mean letting out the clutch slowly - it usually means a touch of throttle as you let out the clutch at your usual speed for doing so.

yes!!! this is what i do.. so i don't actually know if that's considered engine braking. that's for clarifying that...

In stop/start city traffic, you might find that you can spend a lot of time in 2nd or 3rd gear, accelerating for a while and then getting your foot off the throttle and letting the engine braking slow you down. Judging how long to accelerate before easing off the throttle is one of the arts of driving a diesel engined vehicle in such traffic.

Okay now that is too complicated, I'm just going to stick to the basics. hahaha

Engine breaking, on the other hand, for a TDI is any of a number of bad habits, including babying the engine, idling the engine, using the wrong oil, using the wrong fuel, riding the clutch (although that will lead to clutch breaking, not engine breaking) etc.

yes, i've also been riding the clutch! yay! now i know the term... basically I clutch down fully and brake... oh that's bad yeah. okay, this is like learning driving all over

i have to say, i love the boost from the TDi... even though it's a 1.9, it's still heaps more powerful than what i've ever been in!
Thanks mate!

[Logzy]

we really need a forum for manual drivers who have driven auto cars for too long...

Why dont you just go and get a driving lesson.???