Performance diesel fuel

[Foz]

So I always use V power or Tesco 99 for the 911, but have just chucked in supermkt diesel into the oil burners over the years.

Now have the van which is running a lot more power than standard and the 335d.

The only car I have had that really didn’t like cheap stuff was the V10 M5, are the diesel performance versions worth it?

Cheers

[Gavin]

I know a few taxi drivers who swore by it for keeping the engine running cleanly. I used to pop a tank in at least once a month but should try it in the Volvo as for an old tank it shifts.

For something like the 335D I would probably do it for a month or so and see if there is a noticeable difference in economy and performance.

[NGRhodes]

Unlike with many petrol engines, higher cetane rated fuels (which mostly use 2ehn to boost the cetane rating) give a power boost without needing any kind of retune, its well documented and referenced, https://en.wikipedia.org/wiki/Cetane_Improver, not only boosts power, but burns cleaner too.

I use an 2ehn additive and get mine from https://www.hydra-int.com/diesel-fuel.html - works out cheaper than V-power for same (if not better) cetane boost.

[V8Granite]

The biggest difference is in how clean it should burn.

I ran a diesel treatment in my Defender and it ran better. You can get the same from a better quality fuel. I certainly noticed a difference when I first used a tank of BP ultimate diesel a long time ago linked up with a good hard run for a few hundred miles.

Quality fuel (so no water or contaminated TVs in it) and half your fuel filter change to really help. Also try to get some load in the engine each time you use it when warm, this stops nozzle dirt build up as it burns off before cooling and hardening.

Dave!

[Matty]

I've been running SUL on the Up since I had it - I mean, at nearly 60mpg the cost difference over the years is minimal and it does feel better.

I do find you need to experiment a bit. I've always used Tesco99 as it was the cheapest...but recently switched to Sainsbury's SUL and it feels smoother, so I've been sticking to that.

It also has the benefit that barely anyone uses SUL so the chances of catching COVID from the handle are reduced

[Nefarious]

I make a blend to add to cheapo supermarket diesel. Better than super - higher cetane and better lubricants, and costs around an extra 1p per litre.

50% 2-stroke oil
45% Cetane booster ([url=https://www.ebay.co.uk/itm/Hydra-Fuel-C ... %3A2334524]Clicky[url])
5% naptha (Zippo fuel)

Use roughly 1:250 with fuel

[DeskJockey]

I do find you need to experiment a bit.

This. The Mazda didn't like BP normal diesel, feeling flat and down on power compared to other brands. That's the only car of ours I've felt any difference in though. But then none of them have qualified as high performance or been modified.

[16vCento]

Interesting stuff.

Out of force of habit I put V Power in the XF when I picked it up, just because I had to use V Power in my S60, is it much more expensive to put premium diesel in over normal stuff?

I imagine it will be a while until I have to put any more in due to lock down!

The chap I bought my Disco 3 off used to put 2 stroke oil in the fuel and said it was a lot quieter running with it in.

I just stuck any old diesel in it and it seemed no different to me in noise or performance.

[Matty]

I make a blend to add to cheapo supermarket diesel. Better than super - higher cetane and better lubricants, and costs around an extra 1p per litre.

50% 2-stroke oil
45% Cetane booster
5% naptha (Zippo fuel)

Use roughly 1:250 with fuel

I'm not sure I could be trusted with that, I did fail chemistry

[dinny_g]

When I had a 3.0Tdi Audi A5, I’d treat myself to the Premium Diesel if was going in a trip somewhere. I was never sure of any improvement, performance wise was real as it was probably psychological.

My current work fuel card is restricted to normal fuels so I haven’t got the good stuff for years...

[Nefarious]

I was trying to find my old thread about the experiments in the Disco to come to my recipe, but it looks like it's too old.

Basically, I adjusted the fuel pump to the point where there was *just* a little black smoke on WOT using supermarket juice, then did a series of motorway runs. No dyno or rolling road, so my proxy for a power measurement was boost level at an 80mph cruise. I also had an EGT gauge and made a guesstimate of how quickly the numbers rose on WOT acceleration.

Too long ago to remember the exact numbers, but for both experiments: supermarket < super < supermarket + my formula. Plus on the super or formula, I could adjust the fuel pump a little further without smoke.

[Foz]

I make a blend to add to cheapo supermarket diesel. Better than super - higher cetane and better lubricants, and costs around an extra 1p per litre.

50% 2-stroke oil
45% Cetane booster ([url=https://www.ebay.co.uk/itm/Hydra-Fuel-C ... %3A2334524]Clicky[url])
5% naptha (Zippo fuel)

Use roughly 1:250 with fuel

I remember that thread! How do you mix the concoction?

[McSwede]

So I always use V power or Tesco 99 for the 911, but have just chucked in supermkt diesel into the oil burners over the years.

Now have the van which is running a lot more power than standard and the 335d.

The only car I have had that really didn’t like cheap stuff was the V10 M5, are the diesel performance versions worth it?

Cheers

I'll have done well over 700,000 miles on supermarket diesel in various motors with no problem. Some of them doing 80,000-100,000 miles in 2 years.

Not worth the extra. Just fill with cheapest supermarket stuff

[Rich B]

The only car I've had that was "fussy" about fuel was the e46 M3. Obviously it required super, but it wouldn't feel right on some cheap supermarket 98, i ended up sticking to shell and BP and it was fine.

[Mito Man]

A diesel e46 M3

[NGRhodes]

I make a blend to add to cheapo supermarket diesel. Better than super - higher cetane and better lubricants, and costs around an extra 1p per litre.

50% 2-stroke oil
45% Cetane booster ([url=https://www.ebay.co.uk/itm/Hydra-Fuel-C ... %3A2334524]Clicky[url])
5% naptha (Zippo fuel)

Use roughly 1:250 with fuel

I thought 2-stroke oil was an old wives tale (possibly beneficial for the old US derv before it went low sulphur), this study shows it does bugger all for British spec fuel - https://www.fuelexpert.co.za/2-stroke-o ... -study.php

[Mito Man]

I've heard that "new" diesel is shit as it has less lubrication compared to what you got in the old days when it was closer to crude oil. This is only from farmers aged 60+ though. Not sure i'd want to fuck with a modern diesel running on thousands of PSI and equipped with a particulate filter.

[V8Granite]

I make a blend to add to cheapo supermarket diesel. Better than super - higher cetane and better lubricants, and costs around an extra 1p per litre.

50% 2-stroke oil
45% Cetane booster ([url=https://www.ebay.co.uk/itm/Hydra-Fuel-C ... %3A2334524]Clicky[url])
5% naptha (Zippo fuel)

Use roughly 1:250 with fuel

I thought 2-stroke oil was an old wives tale (possibly beneficial for the old US derv before it went low sulphur), this study shows it does bugger all for British spec fuel - https://www.fuelexpert.co.za/2-stroke-o ... -study.php

Definitely works on older diesels, you can hear it and see it especially from cold.

Dave!

[Foz]

Seen this recommended elsewhere..

[Nefarious]

I thought 2-stroke oil was an old wives tale (possibly beneficial for the old US derv before it went low sulphur), this study shows it does bugger all for British spec fuel - https://www.fuelexpert.co.za/2-stroke-o ... -study.php

Interesting.
My own use of 2-stroke in the blend was based mainly on 2 things: first, comments from a chemist at Ineos in reference to the move from EN590 to Ultra-low sulphur diesel and it's negative effects on rubber seals and overall lubricity (note that the linked study only looks at the earlier EN590 standard) and a recommendation to use "some sort of fuel additive"; second, a look at the composition of commercially available diesel additives (e.g. Data sheet for Flashlube Diesel conditioner) - they're basically a refined oil and a little bit of solvent, usually naptha (FYI - "injector cleaner" products are the same, just with a higher % of solvent) - a 95% 2-stroke oil/5% naptha mix is a pretty close copy.
Qualitatively, when I ran the mix in the Disco (without the Cetane booster) the fuel pump was less clattery, the engine appeared to run smoother, and appeared the pick up better on sudden WOT.

It's also worth flagging that the linked study above does not consider the effects on rubber seals, and does appear to show a significant increase in lubricity for EN590 under the SLBOCLE test: