23H8 STG Update for VW T5 GP: Increased Fuel Consumption, Reduced Power

Hello and greetings to you all!

Since autumn 2011, I have been dealing with the issue that the MSG update (action 23H8) performed on the 2.0 CR engines has, in many cases of the T5 GP, including my Multivan Startline CAAC, resulted in an increased fuel consumption of approximately 1 to 1.5 liters and a loss of power in the higher RPM range.

At first, I observed the whole situation for a while; the temperatures had already dropped far below 0°C, and the car was equipped with winter tires. Through surveys on the T5 forum, I realized that I wasn't alone in my observations.

Before the update, my T5 GP, which now only has 16,000 km on the odometer, would quickly accelerate to 170 km/h, and then, after a short wait, the speedometer would show 200 km/h. This happened without the engine seeming strained. Now, it simply stops at 170 km/h; it doesn't go any faster. Above 120 km/h, the engine seems strained. The average fuel consumption was 9 liters per 100 km. In city driving, the average consumption was between 10 and 11 liters, depending on the distance. On the highway, with a speed between 140 and 150 km/h, the fuel consumption was 10 liters.
Currently, we're getting between 13 and 14 liters per 100 kilometers in city driving, and at least 11 liters per 100 kilometers on the highway. On the federal highway, if you can maintain a good, controlled slide, you can achieve real-world fuel consumption figures that are in line with today's technology.

In my case, I always used the same section of highway with the same load for comparison. The city driving remains within acceptable limits. I'm no longer getting 800 km of range with a full tank; the tank capacity is just under 80 liters.

After inquiring with my VW dealer, I received two different answers:
1.) The official response: We are not aware of this issue, and we will send an inquiry to VW, but we do not expect much.
2.) The unofficial one: We're already familiar with this, but he can't do anything about it, as Volkswagen hasn't offered him anything. Many customers are complaining about this issue, and it's not just happening with the T5.

I then saw the reply that was sent to the dealer. The response from Volkswagen stated: "This issue is not known to us." A comparative test drive with a similar vehicle should be conducted.

I haven't laughed this much in a long time. Besides the fact that all the T5 models on the dealer's lot have the same update installed, it's rare for a dealer to simply have a comparable vehicle readily available.

Now, I have contacted Volkswagen directly in writing. Of course, they immediately informed my dealer, who now wants to arrange a test drive with me, specifically:

50 km of highway.
50 km of federal highway.
20 km city.

Everything is logged and then sent to Volkswagen.
I also need to collect and create records for fuel receipts.
Is everything on me?

Is this procedure known?

You'll never be able to achieve the fuel consumption figures listed in the brochure with this car.

Or is this a tactic of attrition, essentially keeping the customer engaged for so long that they eventually give up...?

Regards,

Peter.

Quote:

Or is this a tactic of attrition, like, I keep the customer occupied for so long that they give up...?

This is a first attempt. What comes out --> ?

Without the possibility of a test drive through the , probably nothing can happen from VW's point of view.

Hello!

A lot of time has passed since then, and the following has happened:

After a long waiting period and a personal complaint to VW, a test drive was finally arranged. The setup was that I drove the car, while the workshop manager sat in the passenger seat and monitored the data. The workshop manager himself was not allowed to make this trip because the speed limit on Austrian highways is 130 km/h, and he is not permitted to exceed that speed for that very reason.

Top speed at full throttle on a flat highway with no wind is 170 km/h, possibly even a bit more. On the test, the car reached approximately 160 to 165 km/h, which is definitely not the speed that was previously possible.

This logged data was then sent to VW Salzburg, the Austrian VW headquarters. After repeated inquiries and numerous phone calls regarding this matter, I was informed that another test run will be conducted using a vehicle that is nearly identical.

For a long time, I was told with regret by the service manager at my VW dealership that no vehicle was available for a test drive. Weeks passed. However, yesterday, while I was on the phone with the workshop manager about a different issue, I was suddenly informed that two vehicles were available, and that test drives had been conducted with each of them. According to the information I received, both T5 vehicles reached a maximum speed of... Speedometer range: 175 to a maximum of 180 km/h.

I explained to the workshop manager that while this would still be a small amount, it would confirm the deficiency in my T5, as it would not reach the specified build speed.

Here it comes.

According to the workshop manager, everything is fine, because even my T5 reaches its maximum speed as indicated by the speedometer.

Taking into account the MFA display, which already shows a less divergent value, my T5 doesn't even reach 170 km/h. If we take the value from the "Freundlichen" tester, it's even lower.

As I understand it, we are using the most accurate measuring tools available, which in this case are the testers. Therefore, the most accurate possible value always applies.

Unfortunately, I haven't yet had the opportunity to record the speed using GPS.

How would you proceed from here? Has any new information emerged regarding this issue?

What does the case law say about recording the mileage of a vehicle?

Regards,

Peter.

Hello,

I once inquired at a university, and they had a test setup where the NEFZ (New European Driving Cycle) can be replicated. "As far as I remember, it should cost around 1000 euros, and it would certainly be an acceptable proof of consumption anomalies, recognized by VW."

When it comes to speed tests, qualifying the reference measurement is a bit tricky if an accurate absolute value is required. Who's to say that GPS provides a more accurate speed measurement than the speedometer? Generally speaking, GPS is an inherently less precise method, where the results are typically improved through filtering of the raw measurements. Some sources of error are also difficult to determine (e.g., the number of satellites available at the time of measurement, the strength of signal reception, etc.). I can't estimate that in absolute numbers, but overall, I don't think this method is particularly suitable for determining the speed at a specific point in time with high accuracy.

It might be feasible to create a characteristic curve for the speedometer reading on a rolling dynamometer with a known error in the speed measurement, essentially mapping delta v_world (v_tachometer). That would certainly be a perfectly acceptable vehicle for world calibration, provided that the tire pressure and contact area are reasonably aligned.

Bye.
peace

Hello!

So, in short, it will probably be a report from an expert.

The whole situation isn't developing the way I would like it to, or the way I had hoped it would.

It seems like VW is once again trying to avoid taking responsibility. The comparative tests are supposed to disprove exactly what I've been criticizing.

After posting a question on the T5 forum, "How fast do your T5 GP 140 PS TDI models run?", I mostly received answers indicating speeds exceeding 175 km/h.

The problem is that the brochure promises a speed of "173 km/h in fifth gear." That's probably achievable. And it seems that my bus also meets this requirement, which would invalidate my complaint.

My bus, when I bought it, could reach speeds of 190 to 200 km/h, but the software update turned it into a slow vehicle. This effectively eliminated the positive upward trend in the data series.

Furthermore, the problem of increased consumption remains unresolved.

Regards,

Peter.

Hello,

I hope you're not expecting too much from this.

I think it's quite borderline for a T5 with 140 horsepower to reach speeds of around 200 km/h. My Golf doesn't exactly reach 200 km/h easily, and it has a little over 140 horsepower.
When driving a "big" car with over 300 horsepower, you start to feel the effects of wind resistance quite noticeably at speeds above 190 km/h. In terms of aerodynamics, the T5 and Treg I models are likely to be quite similar, and we can easily drive to our neighbors in Bavaria to legally test this.

I believe it's important to be realistic. The T5, with its current engine configuration, simply lacks the necessary displacement. This "little engine" in such a relatively heavy and bulky vehicle won't perform miracles and certainly won't set any new fuel efficiency records.

(My opinion!!)

If it helps:

With the then-current 170 PS PPD TDI (approximately 2008)), even an update caused the same problems, meaning there was also a lack of power / fuel consumption increased, and drove some owners to frustration because these vehicles only reached 200 km/h instead of the stated ~225 km/h.

SG
Alevuz.

Hello!


I would like the original, old one. Letting the SW stand deflate is usually not a problem.

"This should be something that any tuner should be able to do."

Hello!


I would like the original, old one. Letting the SW stand deflate is usually not a problem.

It should be something that every tuner can manage.

But only with the option to open the control unit. And now, let's think some more about the matter of the warranty.

And that's exactly what I want to "avoid" for now, until I've gone through everything with VW. Next up is the legal route. I still have some time.

Regards,

Peter.

The engine probably had around 180 horsepower originally. I don't think you have any right to expect that. VW likely reduced the engine's power output and average combustion temperature so that the engine would, at least for VW, survive the warranty period.

Best regards.
Christian

The engine probably had a little over 180 horsepower before. You don't have a claim to it, IMHO.

Yes. The 'tolerance' he is allowed to deviate from can be at most 10...15% higher or lower, or something like that, according to various rulings. (Serial spread). If he exceeds that, the manufacturer MUST make corrections .

Yes, VW does. He tuned the engine to produce the 140 horsepower that is stated on the vehicle registration document.

Best regards.
Christian

Actually, VW does. He tuned it to the 140 horsepower that is stated in the vehicle registration document.

Who says it, and where does it stand?

Quote:

Multivan Startline CAAC

In the first post.

Best regards.
Christian

It doesn't say that it was transferred from xxxPS/NM to XXXPS/NM.

Therefore, no one can say they have 140 horsepower NOW. Unless I can't read the post correctly .

A T5 has a large cross-section and does not have a record-breaking Cw (drag coefficient). At high speeds, the top speed is essentially dependent on air resistance. Therefore, the top speed is proportional to the cube root of the engine power. Considering the engine power options that correlate with the speeds mentioned above, and assuming an approximate speedometer error of 10 km/h at 200 km/h, you would end up with approximately 180 horsepower.

Best regards.
Christian