Fuel Consumption: VP vs. PD - Real-World Experiences | Posts 32+

ulf wrote:

According to the DZR (German Vehicle Registration), my car has a respectable 135 horsepower at 1,500 km of mileage, but compared to my old Golf 3, it still drinks a lot of fuel: with the same, economical driving style, the ASZ engine consumes about 5.3 liters, while the AFN engine was satisfied with about one liter less.

Okay, here's another update:

My overnight top-up consumption was 4.1 liters yesterday, which, "adjusted for tire size," is almost at the level of my AFN Golf (with the same driving profile, although with slightly lower average RPM thanks to the 6-speed transmission).
Mileage is approximately 5000 km.

Since I always fill the tank completely, right up to the neck, the overnight fuel consumption is quite accurate and also closely matches the MFA (Multi-Function Display).

The only question now is what's causing it.
Just before the last refueling, I had pushed the car to its limits several times on the highway, exceeding 4000 rpm with full throttle as part of my turbocharger performance tests, something it hadn't experienced before.

Immediately after that, I modified the coolant air duct to direct air towards the low-temperature circuit (LTC), which reduced the LTC temperature by approximately 10K at maximum power. However, this difference is unlikely to be noticeable in everyday operation with relatively low LTC temperatures.

And since the last time I filled up the tank, it's been considerably warmer on average...

Let's see how this develops further.

Hi Ulf! I'm reading with great interest about your constant efforts to make your car even more efficient and your ongoing battle against any kind of compromising comfort. I simply can't understand the effort you put into optimizing fuel consumption by such small margins, considering your low mileage of 3,500 km in 4 months. It seems like the real 'waste' is buying such a vehicle in the first place.

Kannix wrote:

I simply cannot understand your concern about the amount of fuel consumed, whether it's more or less, given your low mileage of 3500 km in 4 months. The real "waste" is buying such a vehicle in the first place.

Well, driving pleasure and interest in cars are difficult to quantify with "reasonable" criteria... but one of today's generally common, comfortable cars with the same engine would have been considerably more expensive .