Low RPM Driving: Harmful to Your Engine?

Hello,

erstmal die Vorgeschichte: Mein Cousin, meine Eltern und ich sind geteilter Meinung, was meine Fahrweise angeht. Ich fahre meist niedertourig und spritsparend (5ter Gang im Ort usw.) und schalte meist bei ca. 2.000 Umdrehungen pro Minute (laut Drehzahlmesser). Mein Cousin studiert KFZ blablabla und meint, dass es schädlich ist, wenn man niedertourig fährt. Das ist natürlich gefundenes Fressen für meine Eltern (40 und 43), welche meinen, dass es schädlich für den Motor ist, da sie es früher eingetrichtert bekamen, dass man den Motor oberhalb der 2.000 Umdrehungen hält (wegen Verrussung usw. was weiß ich noch). Ich konnte dafür keinen Beweis finden, dass es einem modernen Motor schadet (ich halte den 1Z für einen modernen Motor). Sie wollen es nicht begreifen, dass es dem Motor nicht schadet (wieso auch, AGR ist weiter geschlossen (weil ich mehr Drehmoment in den unteren Bereichen möchte), die Einspritzdüsen werden durch den nicht so hohen Druck nicht so stark belastet usw.). Also, wie ist es: Habe ich recht oder nicht? Mich lässt die ganze Sache nicht los (zumal mein Cousin den ganzen Schmaronz studiert). If it's harmful, I will stop doing it in the future and continue revving the engine. If not, I will drive as usual and show my parents the message you sent them.

Best regards, WarLord.

hi,

I wouldn't consider the 1Z engine to be a modern design. The engine concept dates back to the 1970s.

Regarding driving around 2000 RPM, I can tell you that I do the same thing, and I've driven my 1Z for approximately 150,000 km like that. Take a look at the torque curve. You'll see that the engine produces its maximum torque slightly above 2000 RPM! When I was driving my 1Z and Wowa, I usually drove just above 2000 RPM.

What your parents might mean is driving a gasoline engine. These usually require an RPM of at least 2000-2500 to perform well. However, diesel engines are known for producing high torque at relatively low RPMs. There's no reason not to take advantage of that. In any case, I would never consistently rev out a TDI engine, either when shifting or during normal driving!

(especially since my cousin studied all that nonsense).
Greetings, WarLord.

That doesn't mean that he understands it either.

Why would it be harmful? Didn't you ever have that explained to you?

'I usually drive around 1500 RPM in the city, and my engine has been running fine for a long time! Besides, there's no real reason to drive at higher RPMs. It only increases emissions and fuel consumption. Also, 1500-2000 RPM isn't really low even for a diesel engine, and it's still within the usable RPM range of 800-4500 RPM for your engine.'

For example, a diesel truck engine might start burning fuel inefficiently at 2000 RPM.

As long as the engine isn't misfiring, I think everything is fine!

Regards,

Manuel.

Hi,

That's a ridiculous claim.
Everything above the idle speed is fine, as long as the engine doesn't misfire or stumble, and that includes even with a gasoline engine. By the way, it also says that in the owner's manual! So - RTFM!
Also, ask your cousin about the pollutant emissions at both high and low RPMs. Then, he will probably have to admit that they are much higher. What a deliberate environmental vandal!

Hi,

I'm just saying, my old Passat TD has 330,000 kilometers on it . It was generally driven at 50 in the 5th gear... and mechanically, the TD doesn't differ significantly from the TDI.

My father's car, a 1z model, now has 280,000 km and has only seen high RPMs during the vehicle inspection .

Quote:

Take a look at the torque curve. You'll see that the engine achieves its maximum torque slightly above 2000 RPM.

I thought the 1Z reached its maximum value at 1900 ???

By the way, I also drive in a way that I shift to the next gear at 2000 RPM, until there are no more gears left .

Currently, the only annoying thing is a squealing noise at 900-1200 RPM – it's probably the tensioner pulley (the belt tensioner element is new, but the pulley itself might not be).

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

I think a little variety is also good.
Sometimes, when I feel like it, I shift at 1800 RPM (before the turbo kicks in – if I shift at 2000 RPM, the car jerks a bit).
Sometimes I shift into second gear and let the engine run up to 50 before shifting into sixth gear.

You can also comfortably drive at exactly 50 km/h in sixth gear – I don't need to press the accelerator, and I don't need to activate the cruise control because the car maintains that speed on its own.

Sometimes I drive the car (on country roads) up to 3500 rpm, and then the other cars don't bother me anymore .

'On the highway, I usually accelerate to 4000 RPM when there's no traffic, but I also often stay behind trucks in sixth gear.'

Okay: Skoda Superb V6 - with a small switch - 155 hp - and when the car is warm and I want to drive fast, it has 183 hp.
Without the tuning, the car runs more smoothly at lower RPMs – that's why I don't use it when driving slowly.

@joergs


So, I wouldn't describe the 1Z as a modern engine. The engine concept dates back to the 1970s.


Well, what concept are the new 1.9 TDI engines based on?

@Manuel Thomas

Why would it be harmful, haven't you ever had that explained to you?

'For some reason, no one can explain this to me. My mother always says that it's bad for the engine if you accelerate from 50 mph with full throttle (the TDI then vibrates slightly to heavily).'

@Bertil

One more thing: Ask your cousin about the pollutant emissions at both high and low RPMs. Then he will probably have to admit, quietly, that they are much higher. What a willful environmental hooligan!

For now, emissions are a secondary concern; the longevity of the engine is the primary factor.

@dieselmartin

What's currently annoying is just a squealing sound at 900-1200 RPM - it's probably the tensioner pulley (the tensioner element is new, but the pulley itself might not be).


I also hear that squeaking sound (although it's not very loud or annoying). For me, it also happens when I turn on the air conditioning.

Best regards, WarLord.

Sure, here is the translation of the text from German to English:

"Hi,"
I also studied something similar, and I can only say that this is definitely not taught.
Fixed speed specifications are nonsense anyway. At least, one should consider the speed in relation to the maximum or nominal speed (similarity principle: defining key parameters), and in that regard, 2000 RPM on a TDI corresponds to 2500-3000 RPM on a gasoline engine. The example with the truck engines is correct in this case; it's even more pronounced with ship diesel engines.
Do your parents still use "Zwischengas" when downshifting? You definitely had to pay attention to that back in the day.
Generally speaking, bearing failures have become rare. The last case I know of happened 10 years ago, and it turned out something had fallen into the cylinder during a spark plug change...

'No, they don't use a slip clutch. I think they've always only used synchronized transmissions. In my car, low-speed driving looks like this: I usually shift around 2,000 RPM and in town, I mostly drive at around 1,000 - 1,100 RPM. Revving the engine below its idle speed won't cause any damage.'

Best regards, WarLord.

Hello.
I'm sorry if I stray a bit from the topic:

I would like to know which car you have with the 1Z engine and what your fuel consumption is per 100 km.

Regards, R00KIE.

Hi,

I think I now understand why people still say that driving with a low RPM damages the engine.
In the early days of motorcycles, it was difficult to maintain a sufficient oil film between the crankshaft bearings at low engine speeds. This was due in part to the quality of the oil and also to the design of the engine.
This opinion still persists today, but it is no longer relevant. The improved oil quality provides significantly better emergency lubrication. Furthermore, engine designs are now engineered in such a way that a load-bearing oil film exists even at low speeds.

@ROOKIE

The 1Z engine is installed in a facelifted Passat 35i model and consumes approximately 5.2 - 5.5 liters (closer to 5.2) with my driving style. My father's consumption, however, is around 6.5 liters per 100 km, likely because he doesn't let the car coast before stopping and brakes according to the speed limit sign.

@Bertil

I've already told them about this (regarding the oil film). Recently, something similar happened again: I was comfortably driving up the hill in fourth gear (with the car fully loaded), and the torque was sufficient. My mother said, 'Why don't you shift down a gear?' My response was, 'I don't see any reason to shift down.'

Best regards, WarLord.

According to the manual (RTFM ), you should shift gears at engine speeds below 1200 RPM. That's how I do it too, except when I'm just coasting in drive mode.
I wouldn't recommend flooring the accelerator from 1200 RPM, especially not in higher gears. I can't imagine that the extreme pressure would be good for the engine. It's better to aim for higher RPMs and a smoother-running engine.

By the way, this article also contains information about the specific fuel consumption of TDI PD engines.
http://www.tuneline.at/news/110kWPD/110kWPD.htm
This indicates that very low engine speeds do not offer any benefit in terms of fuel consumption. This also aligns with my own observations: below 1500 RPM, the fuel consumption seems to increase again, at least according to the readings from the onboard computer. That's why I only let it idle there occasionally.

I've already told them about this (regarding the oil film). Recently, something similar happened again: I was comfortably driving up the hill in fourth gear (with the car fully loaded), and the torque was sufficient. My mother said, 'Why don't you shift down a gear?' My response was, 'I see no reason to shift down.'


It works like this:


The TDI engine has only been around for just under 10 years. Before that, there were gasoline engines or indirect diesel injection engines. BOTH require you to maintain a certain RPM; otherwise, they won't accelerate properly.
In addition to that, gasoline engines started to sputter, and diesel engines simply ran out of air (literally... they would produce a lot of smoke) when driven at low RPMs.
and then there's the one that belonged to grandpa, with the bearings...
So, about the speed...

This behavior is particularly common among older people, to the point where even TDIs are driven aggressively. You can often see it in cars that have been modified, where someone from the gasoline or /8 community suddenly puts a TDI engine in. They drive them enthusiastically, often exceeding 3000 rpm. If you show them that the TDI starts pulling strongly at just 1500 rpm, they just stare blankly...

CU Gremlin.

Hello,
I'm sorry if I stray a bit from the topic:

I would like to know which car you have with the 1Z engine and what your fuel consumption is per 100 km.

Greetings R00KIE.

Hi R00KIE,

I also have a 1.Z engine in my Golf 3 and it now has 185,000 kilometers on the clock. I usually drive between 1500 and 2200 RPM, and with the last tank of fuel, I managed to cover 1203 kilometers, which translates to a consumption of approximately 4.4 liters. I installed a cruise control system about a year ago and realized that it allows for even more economical and comfortable driving.

Regards,

Maik.