2 hours ago, varaderoguy said:

@Wino @cheezemonkhai Okay - so in that case, what is the EGR used for (to help reduce the temperature of the exhaust gas) & also that is also the point of the Ad-Blue system in my Scout - to convert NOx into Nitrogen and Water.

Really??  I admit I see them queuing up at Morrisons and Asda near me, but that's quite a sweeping statement.  None of us like throwing money away....its all about trying to keep your vehicle running as smoothly as possible for a long as possible.  Additives do help keep things working smoothly.  My experience of supermarket fuels is that it makes the vehicles run lumpy, flat performance and with poor mpg....

 

Because when you make a car breath it's own farts (eg send the exhaust into the intake), then the leftover exhausts gases and water vapour being cooled and pushed back in act to dilute the cylinder gases.  This reduces the ignition temperature of the cylinder. Lower temperature = less NOx formed.
Also there is a reduction in the excess oxygen hanging around (Subject to the engine load/gas requirements), which reduces the opportunity for NOx to form.

The trade off, and why you need ECU control, is if you inject too much exhause gas or do it at the wrong time, then you can increase CO/particulate matter and can reduce engine power output.

 

 

A couple of useful links which may explain some of it:

 

https://x-engineer.org/automotive-engineering/internal-combustion-engines/ice-components-systems/exhaust-gas-recirculation-egr-complete-guide-introduction/
 

https://dieselnet.com/tech/engine_egr_emissions.php
 

https://mbjarvie.co.uk/egr-valve/
 

 

On the supermarket fuel front, I would genuinely love to see a double blind study where people and engineers can tell the difference to the car and it's engine.
Be nice to put it to bed once and for all.
Sure poor quality fuel/off fuel can massively effect a petrol car, but a branded fuel sat in a storage tank for 3 months is likely to be more problematic than fresh fuel in a supermaket tank.

Not saying it's all perfect, but I personally am confident it's not what some think it is.

Same goes for fuel additives. They have their place, but you need to be careful, as evidenced by the issues I've see on other peoples cars.

For a while I used shell almost exclusively (it was cheapest) and it made no difference when I changed away when prices went up.
When i tried a few tanks of the v-power derv, the MPG was noticeably down.

 

I've been running diesels for years and EN590 is way above the fuel requirements for some areas where these engines are sold and used, so I'm more than happy with it. The standard has minimum additive quantities and sulphur levels etc. No car I've ever run has had an issue caused by using whatever fuel I get.

 

At the end of the day it's your car and your money, so it's your choice.

 

Edit:

 

Adding a useful link from a lambda (O2) sensor manufacturer, which details red/white deposits:

 

https://www.denso-am.eu/media/10216/dneu-lambda-sensor-poster-420x594-uk-lo-res.pdf

 

Edited 31 August, 20214 yr by cheezemonkhai
attempt to fix links

12 minutes ago, cheezemonkhai said:

 

Because when you make a car breath it's own farts (eg send the exhaust into the intake), then the leftover exhausts gases and water vapour being cooled and pushed back in act to dilute the cylinder gases.  This reduces the ignition temperature of the cylinder. Lower temperature = less NOx formed.
Also there is a reduction in the excess oxygen hanging around (Subject to the engine load/gas requirements), which reduces the opportunity for NOx to form.

The trade off, and why you need ECU control, is if you inject too much exhause gas or do it at the wrong time, then you can increase CO/particulate matter and can reduce engine power output.

 

 

A couple of useful links which may explain some of it:

 

https://x-engineer.org/automotive-engineering/internal-combustion-engines/ice-components-systems/exhaust-gas-recirculation-egr-complete-guide-introduction/

https://dieselnet.com/tech/engine_egr_emissions.php

https://mbjarvie.co.uk/egr-valve/

 

On the supermarket fuel front, I would genuinely love to see a double blind study where people and engineers can tell the difference to the car and it's engine.
Be nice to put it to bed once and for all.
Sure poor quality fuel/off fuel can massively effect a petrol car, but a branded fuel sat in a storage tank for 3 months is likely to be more problematic than fresh fuel in a supermaket tank.

Not saying it's all perfect, but I personally am confident it's not what some think it is.

Same goes for fuel additives. They have their place, but you need to be careful, as evidenced by the issues I've see on other peoples cars.

For a while I used shell almost exclusively (it was cheapest) and it made no difference when I changed away when prices went up.
When i tried a few tanks of the v-power derv, the MPG was noticeably down.

 

I've been running diesels for years and EN590 is way above the fuel requirements for some areas where these engines are sold and used, so I'm more than happy with it. The standard has minimum additive quantities and sulphur levels etc. No car I've ever run has had an issue caused by using whatever fuel I get.

 

At the end of the day it's your car and your money, so it's your choice.

 

Excellent bit of information thank you I will try and stick to Tesco's petrol and give it a good blast of the motorway every once in awhile

2 hours ago, Diljit said:

Excellent bit of information thank you I will try and stick to Tesco's petrol and give it a good blast of the motorway every once in awhile

 

No worries on the information.
In terms of fuel, just do what you're comfortable and happy with as you are the owner/paying for it.

If you're in warranty read what is said about fuel and additives in your manual/warranty information as a new car warranty is worth a lot more than a few litres of fuel.

When reading the 'Owners Manual' & the Warranty concerning additives, 

remember Skoda / VW Group have Additives that are sold and that at a service you will be asked if you want a Fuel Treatment done.  

 

 

2 minutes ago, e-Roottoot said:

When reading the 'Owners Manual' & the Warranty concerning additives, 

remember Skoda / VW Group have Additives that are sold and that at a service you will be asked if you want a Fuel Treatment done.  

 

 

 

I had no idea that VW had got on the additive train, but then I drive a diesel.
It again makes the point of be careful what is in the additive, as they're not all the same.

I wonder what the base is for that.

They have been flogging their own additive for years and the standard is just the same as others manufacture or retail. 

There were issues in the past with Warranty claims being declined because of the use of additives, but that was cleared up since VW's were the same product.

But then they do try stuff on. 

 

 

Edited 31 August, 20214 yr by e-Roottoot