How to drive a diesel

[A Drive]

Hi, this is my first post.
I’ve recently acquired a 2006 D22 Navara 30D, kitted out for 4WD trips. The odometer reading is 143,000km.
As it’s my first diesel vehicle, I’m receiving plenty of advice on how it should be driven.
Example 1: being a turbo, use the throttle just like a car.
Example 2: Gently push on the throttle and wait for the engine revs to catch up, before depressing the pedal again.
Example 3: Diesels can be lugged, therefore change up early and lug away, especially in fourth and fifth gears.
Example 4: Not being a common rail engine, don’t let it lug; instead keep the revs well and truly up.
Could I have some proper advice on how it should be driven to make the engine and transmission last?
Is there an ideal rev band that the engine should be maintained in to achieve the long life aim?
The vehicle has an exhaust gas temperature gauge fitted and it’s never driven so that the temperature exceeds 600 degrees Centigrade.
As stated before, the vehicle has been set up for 4WD trips, with an extended chassis, heavy duty suspension and an aluminium box with wing doors on the side. All up, the unladen mass is 2500kg, but the approved GVM has been raised to 3180kg.
On a recent trip up the Stuart Highway from Adelaide and around the Mereenie Loop to Kings Canyon and back, we got around 12.6L/100km, which I was not happy with, but presume it’s what I can expect, given the weight of the vehicle. We don’t tow anything.
Regards
Alan (A Drive)

 

[KraftyPg]

Welcome to the forums.

"Proper" advice doesn't exist in a situation like this only opinions do and they vary so much. as you've already seen. that you'd go mad if you tried to make sense of them.

It's a car, drive it like you would any other car, listen to the engine it will tell you if you are doing anything wrong and look after it by giving it a service every 10,000ks, chances are if you do that it wont ask much else of you.

 

[joshman]

Firstly, WELCOME TO THE FORUM! hope you find your stay to be productive and helpful!

I'm interested to see the chassis extension and pics of the vehicle in general.

with regards to driving style, i have the same model of navara, so here's a few tips that i've learnt.

don't let them lug, if you can help it. that's a sure fire way to raise your exhaust gas temperatures and waste fuel by not burning it efficiently and blowing clouds of black smoke (unburnt fuel) When it lugs, you're pouring in fuel, but not creating the necessary exhaust gases to drive the turbo enough to provide it with enough air to efficiently burn the fuel - hence unburnt fuel being expelled out the exhaust.

this also raises the temperature of everything int eh engine block, and in general is not healthy (as best i know).

Have a look around the forum for the EGR and swirl mod (there's more than a few threads devoted to just this), and look at installing a catch can.

As for knowing when to change.... that's something you've got to feel when you drive. i use the 2-2.25k rpm as a good guide for when to change, as you drive it more and more, you'll find out where the ideal change point is for your vehicle, ideally at the top of the torque band is where it should happen - and again, as you drive it more and more, you'll find out where this is.

as for your fuel economy, that sounds about right. given the weight of the vehicle. Also, anything and everything you do to the truck will have an effect on your economy. lift kits, roof racks, tire pressure, wheel alignment tray style and weight. - so be mindful of it.

and one final thing - how on earth do you increase the RGVM?

 

[tweak'e]

The vehicle has an exhaust gas temperature gauge fitted and it’s never driven so that the temperature exceeds 600 degrees Centigrade.....

is it pre turbo or after?
600c after turbo sounds like its been chipped or somethings wrong. pre turbo its not bad and well in the safe range.

this engine is a little odd as it has a short peak power range, peaking at 3500 rpm. so short shifting and lugging it doesn't work well as your off the power and you will crawl along.

 

[Bryce]

What size tires are you running?
An increase of tire size from standard will affect odometer readings, You may have traveled further than reported thus making your L/100Kms better.

Welcome to the forum

 

[jaymac90210]

In regards to lugging the nav, I shift at 2-2200 rpm at the most and it pulls okay... No chip just 3 inch exhaust and Egr, so Would I be damaging my navs engine?

 

[A Drive]

Thanks jaymac for the comment.

 

[jaymac90210]

Thanks jaymac for the comment.

No worries mate, been driving like that since she first drove off the showroom floor and now 174,000k's later and still starts and runs like new

 

[A Drive]

Exhaust gas temperatures & power bands

is it pre turbo or after?
600c after turbo sounds like its been chipped or somethings wrong. pre turbo its not bad and well in the safe range.

this engine is a little odd as it has a short peak power range, peaking at 3500 rpm. so short shifting and lugging it doesn't work well as your off the power and you will crawl along.

Thanks for responding, Tweake.

The exhaust gas sensor is fitted after the turbo and I was advised that it reads 100 degrees lower. In other words, I was told to not let it exceed 500 degrees C on the gauge. To simplify things, I added the 100 degrees.

In regards to the power range, can you tell me, or point me to where I can find out what the lower limits are?

Alan.

 

[A Drive]

Thanks Krafty.

I guess keep it simple and use common sense is the message.

Cheers,

Alan

 

[A Drive]

and one final thing - how on earth do you increase the RGVM?

The previous owner had an engineering workshop extend the chassis and beef up the suspension to carry the weights that he used to take away on his trips.

To ensure that he was legal and insurable, the workshop engaged a mechanical engineer who supplied a certificate that the Motor Vehicles Department accepted.

If you want, I could scan it and post it.

Cheers,

Alan

 

[jaymac90210]

Thanks for responding, Tweake.

The exhaust gas sensor is fitted after the turbo and I was advised that it reads 100 degrees lower. In other words, I was told to not let it exceed 500 degrees C on the gauge. To simplify things, I added the 100 degrees.

In regards to the power range, can you tell me, or point me to where I can find out what the lower limits are?

Alan.

On paper it states the Navara's peak torque is 314nm at 2,000 rpm for the ZD30 and for the YS25 it's 304nm at 2,000. In mine however I feel it pulls fairly strong from around 1500rpm to about 2,700. Might be just me but anyway that's what I feel. I tow my track car to racetracks all re time with the nav and she does it quite well

 

[KraftyPg]

Thanks Krafty.

I guess keep it simple and use common sense is the message.

Cheers,

Alan

I've driven heaps of diesels over the years and to be honest the only ones that have every really caused me any regular issues are ones that have been driven hard and careless. The idea about diesels needing to be treated hard, have their neck wrung or blow the cobwebs out in my opinion is bullshit, they might handle such things better than other engines but they don't need it to survive.

However they also don't need to be pampered, they are fairly resilient and unless you put them under the most extreme conditions like constant desert crossings, dust and high revving etc most of them will happily chug along for a long time with little attention.

Basically treat it like you would any car because it's not really that much different to every other car on the road.

 

[jaymac90210]

I've driven heaps of diesels over the years and to be honest the only ones that have every really caused me any regular issues are ones that have been driven hard and careless. The idea about diesels needing to be treated hard, have their neck wrung or blow the cobwebs out in my opinion is bullshit, they might handle such things better than other engines but they don't need it to survive.

However they also don't need to be pampered, they are fairly resilient and unless you put them under the most extreme conditions like constant desert crossings, dust and high revving etc most of them will happily chug along for a long time with little attention.

Basically treat it like you would any car because it's not really that much different to every other car on the road.

Couldn't have said it any better mate you're spot on. Diesels are designed to rev low, they won't be winning no quarter mile drag races and that's exactly how diesels are meant to be! Treat a diesel well and they will run forever.

 

[tweak'e]

Thanks for responding, Tweake.
The exhaust gas sensor is fitted after the turbo and I was advised that it reads 100 degrees lower. In other words, I was told to not let it exceed 500 degrees C on the gauge. To simplify things, I added the 100 degrees.
In regards to the power range, can you tell me, or point me to where I can find out what the lower limits are?
Alan.

pays to quote guage temp and mention it after turbo. i doubt its a 100c difference, generally most engines are more than that.


they tend to have a 2500-3500 rpm power band.
things like exhaust, chipping change all that.
in stock form they don't pull all that well in the low rpm. i think thats primarily due to lack of fuel in the low rpm due to emissions. chipping it tends to fix it.

 

[Old.Tony]

Welcome to the forum, Alan.

That EGT gauge won't be 100C out - the temperature variation will depend on how much energy the turbo is taking from the exhaust. It could be as low as 20C (around idle) or as high as 200C (around full throttle at moderate to high rpm).

Diesel engines do work differently to petrol but they are fundamentally the same thing - a compressed fuel/air mix is ignited forcing the piston away from the cylinder head, causing the crankshaft to rotate.

Because diesel burns slower than petrol, there's a more prolonged force on the piston and there's a limit to how hard you can rev the engine - the fuel has to be allowed to burn completely or it's just being wasted. The end result is that a diesel engine produces more torque and does it at lower RPM than a petrol engine. About the only change you need to consider is that you don't need to red-line the diesel to make it go places.

The only single thing I'd say that you MUST do is look after your turbocharger. If you've been driving on a highway or driving up a hill, the turbo will be hot - quite possibly a LOT hotter than your EGT gauge is indicating - and it needs to cool down before the flow of oil is stopped, because if the turbo housing is still hot the oil inside the bearings will cook, forming hard deposits inside the bearings which will eventually destroy the bearing, causing the destruction of the compressor which will then disintegrate and find its way into your engine.

The way to combat that - if you've been boosting (hot turbo), let it idle for a couple of minutes. If you're approaching your destination, just back off and let the car cruise to a stop.

Oh, and diesels don't like LOTS of unleaded fuel in their tank.