Fuel

[Graeme 1978]

Hi just a quick question has anyone noticed that when your car does a regeneration does it use more fuel.
Am only asking because a noticed my fuel gauge seemed to take a nose dive when it done the regen.
So a put £25 of diesel in the gauge went to just below 1/2 way the car done it's thing and after 45 miles of driving a noticed my fuel gauge was 1 line above 1/4 of a tank to me it seems as it's just drank the fuel.
Is this right / wrong / or reasonable any advice please.
It's a E class w212 2.1 auto 2012 plate

Sent from my SM-A520F using Tapatalk

 

[Srdl]

The fuel consumption will always go up when it does a regen because the system basically injects diesel into the DPF to burn off the particulates and the gearbox lets the car stay in a gear longer so the higher revs create heat as well. Whether or not it would make the difference you speak of I don’t know - I got rid of my diesel more than two years ago!

 

[John Laidlaw]

^ Exactly this ...

 

[Tony Dyson]

While cruising @ 74 MPH in 7th @ around 1500 RPM and a regen starts, the speed, gear 7 and RPM never changes and the regen completes successfully on every occasion it has been monitored, fuel consumption will be increased during a regen but I have never noticed a decrease in the fuel gauge indicated levels!

 

[Tony Dyson]

Below FYIP is an excerpt from an MB Document 'MB OM651 System Description' detailing exactly how the exhaust gas temperature is raised to around 700° C during a Regeneration phase.

DPF regeneration
The DPF differential pressure sensor reports the load
condition of the DPF to the CDI control unit. If the load
of soot particles is too great and exceeds a limit value
stored in a performance map, the CDI control unit
initiates the regeneration phase when the load condition is suitable. Regeneration takes place by periodically increasing the exhaust gas temperature.
The soot particles stored in the DPF are largely burnt
off to produce carbon dioxide (CO2). Approximately
99% of soot particles are reduced. The residual ash
which is produced remains in the DPF.
The regeneration times are dependent on temperature
and decrease significantly as the exhaust gas temperature rises. The following measures are used to
increase the exhaust temperature:
• Post injection
• Exhaust gas recirculation with intake air throttling
• DPF glow function
During regeneration, the exhaust temperature is monitored by the temperature sensor upstream of the
turbocharger and the temperature sensor upstream of
the DPF.

 

[Graeme 1978]

Thanks 4 the replys just noticed a got replys.

A was just curious as the fuel gauge just seemed to nose dive if a had a deisel leak that would explain it but that said and done just seems really really bad on fuel can't wait to get rid of this car as a taxi it's horrendous.

Thanks again 4 the replys

Sent from my SM-A520F using Tapatalk