Fuel-Efficient TDI Cars: Save Money & Enjoy!

Hello,

How does the OEM manage to achieve a combined fuel consumption of 4.6 liters per 100 km and 119 grams of CO2 for the 2.0L CR-TDI (143 hp) engine in the Ibiza 6J (catalog weight 1170 kg without driver), despite the restrictions?

For comparison:
The 1.9 liter 130 hp PD-TDI (BLT) engine in the previous generation 6L model (catalog weight of 1180 kg without driver), when running without a clogged particulate filter, is specified as having a fuel consumption of 5.2 l/100km and CO2 emissions of 139 g.


Do Common Rail diesels inherently have a higher efficiency (due to fewer losses in the injection system) that makes them superior, or could PD-TDIs potentially achieve similar fuel economy, but then fail to meet the required emission standards?

Hello Ulf,

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or could the PD-TDIs run just as efficiently, but then fail to meet the required emission standards?

certainly.

For a realistic fuel consumption of an Audi A3 8P with a 2.0 TDI CR 140PS engine (EU5 emission standard, DPF) and a manual 6-speed transmission, you can expect around 5.5 liters per 100 kilometers. However, with extra features (e.g., electric windows, automatic climate control always on, just like in the 8L model), and driving in hilly/winding terrain, fuel consumption will be higher.

The fuel consumption is virtually identical to my previous A3 8L with a 1.9 TDI engine, 110 horsepower, without a DPF, but with modifications designed to reduce fuel consumption.

Regarding the engine and transmission, there's nothing to complain about; it's a clear improvement.

Best regards, Rainer.

What about these "Blue TDI" models that have been offered for about a year? Do they already have the SCR system? Perhaps that's the reason for the low fuel consumption figures, and in some cases, they even meet Euro 6 standards.

What I've noticed about the new engines is that the range within which they operate efficiently is becoming narrower.

"You can drive our 90 HP VEP however you like; it's hard to average more than 6.5 liters per 100 kilometers. I can also drive my PD model economically, but it requires real effort. The same goes for the CR models I've driven."

Yes.

The 143 hp 2.0 CR BlueTDI engines have urea tanks and SCR catalysts.
See SSP 424.

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

Therefore, the question posed by Ulf, as to why the CRs have suddenly become so economical, is now answered .

vwSchrauber wrote:

Therefore, the question from ulf about why the CRs are suddenly so economical

is, in my opinion, not entirely answered, because nowhere in the Seat equipment and data PDF or model catalog for the 6J does it mention anything about a BlueTDI .

I'm still unsure.

Because I wouldn't consider horsepower to be proof of a motor anymore; that's a thing of the past.

The 1.4 TSI engine also has 110 kW in the 6J model, while the Golf has 118 kW - even though they are essentially the same engines.
It could also be a simple 140 hp TDI engine with only minor modifications in the 6J model.
The seat.de website only shows the Alhambra when searching for "SCR".

Unless you find the SCR catalyst or the urea tank among the parts for the 6J model.
However, the 2E0 919 050 S part is only available for the Alhambra.

The 6J model uses the CFHD engine, which has a base version (CFH) that produces 140 horsepower in other models.

90% on NOT SCR


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

ulf wrote:

... Do CR-Diesel engines inherently have a higher efficiency (due to fewer losses in the injection system?) to the extent that this is easily achievable, or could PD-TDIs run similarly efficiently, but then fail to meet the required emission standards?

First, the CR (Continuous Rotary) inherently has a lower efficiency because it puts more energy into generating pressure than the PD (Piston Displacement) system does – specifically, it uses continuous high-pressure generation compared to the PD's pulsed pressure generation.

Secondly, it would likely be embarrassing if a lighter vehicle with significantly improved aerodynamic performance consumed more fuel.

Thirdly, the "one-third mix" values offer absolutely no basis for comparison... The use of start-stop systems and similar gimmicks reduces urban consumption, which significantly affects the one-third mix.

Fourthly, it would be even more embarrassing if an ultra-modern injection system were actually superior to a system that stopped development seven years ago. And honestly? For me, the reduced fuel consumption is still too small. The consumption needs to easily and significantly drop below the 4.3 liters mark.

Fifthly... have you ever tried to recreate this "thirds mix" in reality? Well, I wish you good luck with that .

Sixthly... Have you ever driven a CR before? I've driven several, and something is missing... the power from below. These things are so boring to drive... ... So, Ulf, you would be cursing .

Current CR systems operate with a ZME (Zumesseinrichtung). This valve limits the amount of coolant injected into the rail. Consequently, the throttling function previously implemented in the RDR valve is no longer necessary. Therefore, it is no longer necessary to throttle compressed coolant.

Combining downsizing concepts to achieve useful power output (1.6L) allows for significant optimization that meets current emission limits. And a long gear ratio makes the whole thing perfect, thanks to the testing cycle.

Bertil wrote:

Firstly, the CR inherently has a lower efficiency because it puts more energy into generating pressure than the PD does -> specifically, continuous high-pressure generation versus pulsed pressure generation.

. . . However, even with the PD (at high motor load), a tremendous amount of waste heat is generated, which necessitates a return cooling system towards the tank.
According to the records, the CR diesel engines in the Ibiza 6J no longer have a dedicated oil cooler.

Diesel_Rudi wrote:

Current CR systems operate with a ZME (Zumesseinrichtung). This valve limits the amount of fuel injected into the rail. Therefore, the throttling amount in the RDR valve used previously is no longer necessary. Thus, throttling compressed fuel is no longer required.

Hmm, according to the documentation, the 2L TDI engine in the Ibiza still has a "pressure regulating valve 1800 bar" at one end of the rail. At the other end is the pressure sensor.

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Secondly, it would probably be embarrassing if a lighter vehicle with significantly optimized aerodynamic values consumed more fuel.

According to catalogs, the new Ibiza with the 2.0 TDI engine is only 10 kg lighter than the old 6L model with the BLT engine.
A top speed of 210 km/h with 143 horsepower versus 208 km/h with 130 horsepower doesn't seem to indicate significant differences in aerodynamics to me .

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Thirdly, with the "Drittelmix" values, there are absolutely no more possibilities for comparison... The city consumption is reduced using start-stop systems and similar gimmicks, which significantly affects the "Drittelmix".

Yes, in the Ecomotive Ibiza with its toy TDI engine, but IMO not in the 2.0l TDI. Its out-of-town fuel consumption of 3.9 is even lower than the 4.3 of the BLT.

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Fifthly... have you ever tried to replicate this "three-way mix" in reality? I wish you good luck with that.

Is it easier to achieve the standard value with PD-TDIs compared to CR engines? This would then imply, conversely, that they are specifically (and less practically) tuned to consume very little fuel, especially (only) within the operating points of the standard cycle?

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Sixthly.... Have you ever driven a CR? I've driven several, and something is missing... the power from down low. These things are so boring to drive....... .... So, Ulf, you would swear

That might very well be. This thread doesn't mean that I'm thinking about replacing my technically "outdated" BUK with a 2.0 TDI .

Modern CRS systems are superior to PD systems. Unfortunately! I also believe that engines should be optimized for emissions, rather than designed to meet a specific cycle standard. However, it's worth noting that the CR1 system only required 1/9 of the necessary pump drive torque. That significantly changes things.

Compare the actual compression ratios (for reducing NOx emissions). You will inevitably find that new engines cannot be better due to regulations. Increased fuel consumption is an inevitable consequence of normal operation, as efficiency must decrease. This can be understood through a simple pV diagram. Best regards.

ulf wrote:

... however, the power drive (under high engine load) still generates a significant amount of waste heat, which necessitates a return cooling system towards the tank.

So far as I know, the CR system doesn't pump fuel through the cylinder head like the PD system does. However, it's possible that Ulf has different information ...

Quote:

According to the records, the CR diesel engines in the Ibiza 6J no longer have a dedicated coolant cooler for the diesel fuel.

Since the waste heat from the ZK (presumably a reactor core) is not being utilized, it will still be possible to manage the residual heat from the return flow even without a fuel cooler.

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According to the catalogs, the new Ibiza with the 2.0 TDI engine is only 10 kg lighter than the old 6L model with the BLT engine.

Small animals also make a mess...

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A top speed of 210 km/h with 143 horsepower versus 208 km/h with 130 horsepower doesn't seem to indicate significant differences in aerodynamics to me .

Have you ever compared both sixth gears? The one in the CR is much longer. That's why it can't reach that top speed anymore because it simply runs out of power.

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"Yes, in the Ecomotive Ibiza with its small TDI engine, but I don't think so for the 2.0L TDI. Its highway fuel consumption of 3.9 is even lower than the 4.3 of the BLT."

Even with the 2.0 TDI engines, these features exist... Although they may not necessarily include a start-stop function. However, they do have a much more effective load management system. For example, the alternator may not charge the battery at all during city driving to avoid unnecessary loads. The battery then has to compensate for this. When the battery's charge runs low, it is recharged... The entire onboard network has become very complex with its controls... I'm already dreading the "malfunctions" that might occur.

Sure, here's the translation:

"In addition, the translations have been further optimized for fuel efficiency."

Quote:

Is it easier to achieve the standard values with PD-TDIs compared to CR systems? If so, does this mean that they are specifically tuned (and less practical) to consume very little fuel, especially only within the operating points of the standard cycle?

... without further comment from me (I mean, you can imagine what that means)!

Quote:

... This thread also doesn't mean that I'm considering replacing my technically "outdated" BUK with a 2.0 TDI

.

Well, I would have been surprised if you were going to give up your "completely outdated diesel engine" . I wouldn't do that either. Or what do you think the reason is that my even older AXR is still with me...? And why I have such a "Stone Age Japanese car" as a second car...?

Diesel_Rudi wrote:

Moderne CR Syteme sind den PD Systemen überlegen. Unfortunately!

Yes, that's right. However, it's also because the further development of PD (Plasma Display) systems was largely put on hold in 2005, while work continued on the cheaper CR (Cathode Ray Tube) systems. This unfortunately makes the system comparison a bit misleading.

Bertil wrote:

Quote: According to the catalogs, the new Ibiza with the 2.0 TDI engine is only 10 kg lighter than the old 6L model with the BLT engine. Small things also create a mess...

Of course, but the normal consumption-relevant momentum within the EU cycle is varied in steps of 110 kg for vehicles in the small car weight class.
What do these 110 kg represent in the case of the TDIs?
According to the KBA emissions catalog, for example, the BLT (Broadband Lambda Sensor) was measured in the Polo with curb weights of 1250, 1360, and 1470 kg -> the fuel consumption changed by 0.1 liters per weight class, and CO2 emissions changed by 3 g/km for each level.
Speculation: Even if the CR-Ibiza narrowly avoided being classified in the next higher weight class for testing purposes, more "honest" (according to official standards!) fuel consumption figures would likely only be about 0.1 liters higher.

Quote:

Have you ever compared both sixth gears? The one on the CR is much longer. That's why it can't reach that maximum speed anymore because it simply runs out of power.

And does it over-rev in 5th gear, exceeding the theoretically possible Vmax and entering the rev limiter zone?

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Even with the 2.0l TDI engines, these features exist... Although they may not necessarily include a start-stop function. However, there is a much more effective load management system. For example, the alternator may not charge at all during city driving to avoid unnecessary loads. The battery then has to compensate for this. When that charge runs out, the battery is recharged

... which, due to the more cyclical operation, tends to wear it out faster and therefore requires expensive replacement sooner?
The OEM is likely to resort to any trick, no matter how small, to achieve minimal consumption advantages at the expense of the customer's account .

Quote:

Quote: Is it easier to achieve the standard value with PD-TDIs than with CR engines? This would then imply, conversely, that they are specifically tuned (and less practical) to consume very little fuel, especially (only) at the operating points of the standard cycle? .... without further comment from me (I mean, you can imagine what that means)!

No hitting equals consent?

Quote:

Well, I would have been surprised if you gave up your "completely outdated diesel engine" ..... I wouldn't do that either. Or what do you think the reason is that my even older AXR is still with me...? And why I have such a Stone Age Japanese car as a second car...?

There's something in another signature here on the forum, like "Only those who know new cars love the old ones".

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And on the 5th gear, does it over-rev to a point where it goes significantly beyond the theoretically possible Vmax and into the rev limiter range?

I haven't tried it yet...

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... which causes the battery to wear out more quickly due to the increased number of cycles, and therefore necessitates expensive replacement sooner than expected?

It might be...

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The OEM is likely to resort to any trick, no matter how small, to achieve minimal consumption advantages at the expense of the customer's account .

Ahhhh... already awake ?

But as is often written in car reviews: "...with these (missing) features, the vehicle is not competitive...". So, conversely... the customer ultimately demands these features (in this case... lower fuel consumption).

At the same time, the increasingly complex electronics also require a "larger" battery.

Quote:

No spanking equals consent?

Bertil wrote:

ulf wrote: Yes, with the Ecomotive Ibiza and its "toy" TDI engine, but I don't think so with the 2.0L TDI. Its highway fuel consumption of 3.9 is also lower than the BLT's 4.3. Even with the 2.0 TDI engines, these features exist... Although they may not necessarily include a start-stop function. However, they do have a much more effective load management system. For example, the alternator may not charge the battery at all during city driving to avoid unnecessary loads. The battery then has to compensate for this. When the battery's charge runs out, it is recharged... The entire onboard network has become very complex with its controls... I'm already dreading the "malfunctions" that might occur. Sure, here's the translation: "In addition, the translations have been further optimized for fuel efficiency."

Hi,

What hasn't been mentioned in this discussion is that the Ibiza with the 2.0 105kW TDI engine has an "optical shift recommendation" (as do many new cars). This means that the cycle no longer needs to be run through using the gears prescribed by law, but can be shifted as the vehicle recommends (or as the developer intended - e.g., using 6th gear even below 100 km/h, etc.).


Best regards,
Crunch.