Which Diesel

[KenD5]

Hi All

Is it worth the extra to run my D5 on Shell V power or similar. Will it help with regard to DPF and smoother running or is it not worth the money.

Cheers in advance.

[JimG]

I started a thread on this a few years ago.

http://www.volvoforums.org.uk/showth...ighlight=Shell

I still use V-Power primarily, and the BP version otherwise.

[KenD5]

Fantastic Read. Thank you for that. I instinctively put V power in as I assumed this to be beneficial for the engine with regard to the cleaner running. Seems its the way to go. I was at Goodwood for a track day ( Spectator) and had a chat with a guy who had a GTR running approx. 600 bhp. He said he only ran the car on V power as it ran like 'poo' on anything else.

Cheers

Ken

[martin93]

Originally Posted by KenD5

Fantastic Read. Thank you for that. I instinctively put V power in as I assumed this to be beneficial for the engine with regard to the cleaner running. Seems its the way to go. I was at Goodwood for a track day ( Spectator) and had a chat with a guy who had a GTR running approx. 600 bhp. He said he only ran the car on V power as it ran like 'poo' on anything else.

Cheers

Ken

A petrol GTR will need V power fuel since it's a high performance engine with a high compression ratio, so therefore needs a higher octane fuel which burns slower. A lower grade fuel (less than 98 RON) will cause detonation or 'pinking', which causes a loss of performance.

However, I struggle to see what benefit V power diesel makes. I'm not knocking it (haha, 'knocking' it) because I haven't tried it. Diesel engines are a completely different ball game to a petrol GTR. They will always knock and detonate, because that's just how a compression ignition engine works. There's no such thing as an octane rating in diesel, because there isn't any octane. So I guess V power diesel just has more additives to make it burn cleaner? Whereas V power petrol has more octane to make the fuel burn slower and more controlled. A 'whoosh' more than a 'bang'.

[Dancake]

Originally Posted by martin93

A petrol GTR will need V power fuel since it's a high performance engine with a high compression ratio, so therefore needs a higher octane fuel which burns slower. A lower grade fuel (less than 98 RON) will cause detonation or 'pinking', which causes a loss of performance.

However, I struggle to see what benefit V power diesel makes. I'm not knocking it (haha, 'knocking' it) because I haven't tried it. Diesel engines are a completely different ball game to a petrol GTR. They will always knock and detonate, because that's just how a compression ignition engine works. There's no such thing as an octane rating in diesel, because there isn't any octane. So I guess V power diesel just has more additives to make it burn cleaner? Whereas V power petrol has more octane to make the fuel burn slower and more controlled. A 'whoosh' more than a 'bang'.

The octane rating partially relates to the ignition resistance of petrol. In higher compression ratio engines, you need a higher octane rated fuel in order to prevent pinking or pre-detonation of the fuel. Lower grades of fuel won't necessarily cause pinking or knocking. That's what your knock sensor is for. It will retard injection timing to prevent pinking if it senses premature detonation of the fuel. Modern cars must be able to run cleanly on the cheapest, minimum legal specification fuel available at the pumps, hence the introduction of emissions controls and knock sensors etc. I am unsure what you mean with regards higher octane fuel burning slower? Perhaps you are referring to it in the context that it takes slightly longer for the ignition of higher octane fuel to occur. The burn rate however is just as quick as that of lower octane rated fuel.

Diesels have a cetane rating, which partially relates to the fuels resistance to ignition delay. The higher the cetane rating, the less resistance it has to ignition. The engine management system can inject the fuel knowing that the higher cetane fuel will ignite within a certain time frame. Lower cetane fuels would have to be injected earlier, as they take slightly longer to reach their flash point. Longer ignition delay = less performance = less fuel efficiency etc. This is one of the reasons as to why it's better to run a diesel on higher cetane fuel.

[JimG]

I also read on this forum that the D5 engine is prone to valve seat wear. The removal of sulphur from diesel accelerates the problem because the sulphur acts as a lubricant. V-Power and the like have added lubricants and so help prevent this wear.

It may cost more, but my engine is noticeably quieter, quicker, and I get better mpg. Although the increase in mpg doesn't offset the added cost, I still think it's worth it for the other added benefits.

[5cilinder]

I doubt that dieselfuel with or without suphur can lubricate valveseats if the fuel is injected with closed valveseats
And the removed sulphur is replaced with an additive that compensates lubrication and with the addition of biodiesel its lubricated more than ever
(yes there was a time that the sulphur was removed and not additized that wroke havoc on fuelpumps) but that time is long gone

[skyship007]

I would not bother using top of the range diesel fuel as it's cheaper to keep the injectors clean by topping up the fuel filter housing when the element is changed. Just use a major brand direct feed cleaner like Liqui Moly Diesel Purge. It saves time using the priming pump after the filter is changed or inspected.

It is worth sticking to major brand fuel stations, as they check their filters more often and don't use fuel that lacks the EU minimum additive levels. Shell or BP in the UK, or Aral (Owned by BP) and Shell in the EU.

Most engine fuel filters can last from 10 to 20K miles, BUT don't push your luck cos some HP pumps can split the element of a full one.

[GusGecko]

Originally Posted by JimG

I started a thread on this a few years ago.

http://www.volvoforums.org.uk/showth...ighlight=Shell

I still use V-Power primarily, and the BP version otherwise.

Interesting reading..... I usually put in bp ultimate in every now and again, I've also tried millers eco max. Im not sure I can tell much difference

[phil1968]

Originally Posted by martin93

A petrol GTR will need V power fuel since it's a high performance engine with a high compression ratio, so therefore needs a higher octane fuel which burns slower. A lower grade fuel (less than 98 RON) will cause detonation or 'pinking', which causes a loss of performance.

However, I struggle to see what benefit V power diesel makes. I'm not knocking it (haha, 'knocking' it) because I haven't tried it. Diesel engines are a completely different ball game to a petrol GTR. They will always knock and detonate, because that's just how a compression ignition engine works. There's no such thing as an octane rating in diesel, because there isn't any octane. So I guess V power diesel just has more additives to make it burn cleaner? Whereas V power petrol has more octane to make the fuel burn slower and more controlled. A 'whoosh' more than a 'bang'.

Shell V-Power, along with all Premium fuels has a higher cetane rating (which is the diesel equivilent to octane) than regular diesel fuel. I use a cetane booster added to the fuelin my D5 which works out cheaper than using premium fuel from the pump