[HighlandPete]

Originally Posted by 335diesel

This proves my point - everyone's "better" experiences are based on "what it feels like" - nothing to back it up. You may be looking for more performance because you've just spent a load extra on filling up?.

We have to go by feel and mpg results, if we don't dyno our cars. Dyno tests have been done and on the 'enhanced' fuels, they do show positive results. Even one of our UK TV motoring programs did, and they recorded extra bhp.

As I say, read the technical data, look at the evidence that show cleaner engine parts do exist as a result of cleaner fuel. Even the smoke tests show there isn't as much soot going through and engine. Engines have been 'split in half' running two different fuels and compared...

BTW, there is a lot of material out there, Ford for example, worked with BP on the Ultimate fuel, they state they wanted a cleaner fuel for the latest generations of CR diesels, to assist keeping injectors in top condition, and keeping emissions down. It is all out there to research and digest.

HighlandPete

[335diesel]

If there were genuine, conclusive results, the fuel companies would be shouting from the rooftops about them. They don't - they stick to vague "promises" and no real facts.

Same with a few magazine tests that have been carried out - nothing truly conclusive.

If they could state that "super" fuels kept an engine X% cleaner, gave a Z% increase in mpg and/or a Y% increase in power then maybe I'd consider it. I've yet to see a single study that has convinced me.

It's a no brainer for the fuel companies - throw some marketing cash into promoting them, add (apparently) a few cheap additives, whack the price up by 5++%, sit back and watch the cash roll in.

I am a serious sceptic when it comes to many auto industry marketing led claims (hence my dislike of M Sport and S Line type kits that do zilch for performance - in fact they probably reduce it) - possibly to the point of being a little bloody minded!

[Dave_3]

Originally Posted by 335diesel

This proves my point - everyone's "better" experiences are based on "what it feels like" - nothing to back it up. You may be looking for more performance because you've just spent a load extra on filling up?

On the contrary, all the anecedotal comments that seem to back the Oil Companies' claims would suggest otherwise.

If you haven't tried it yourself, you are strongly postulating about something you have no experience of at all. Which isn't a strong poistion to criticise what other have experienced first-hand.

Or perhaps you have tried it - and you are relating your own findings about "what it feels like" - something you dismiss.

Either way ....

D.

[toxicnerve]

Originally Posted by 335diesel

If there were genuine, conclusive results, the fuel companies would be shouting from the rooftops about them. They don't - they stick to vague "promises" and no real facts.

Same with a few magazine tests that have been carried out - nothing truly conclusive.

If they could state that "super" fuels kept an engine X% cleaner, gave a Z% increase in mpg and/or a Y% increase in power then maybe I'd consider it. I've yet to see a single study that has convinced me.

It's a no brainer for the fuel companies - throw some marketing cash into promoting them, add (apparently) a few cheap additives, whack the price up by 5++%, sit back and watch the cash roll in.

I am a serious sceptic when it comes to many auto industry marketing led claims (hence my dislike of M Sport and S Line type kits that do zilch for performance - in fact they probably reduce it) - possibly to the point of being a little bloody minded!

I get what you are saying. However, it would be virtually impossible to quantify in this sort of way because every car is different and every driver has a different driving style.

I could go out and buy an M3, fill it up with premium and get 30mpg out of it. Someone else could do the same thing and only see 15mpg.

The question is, how were the two cars driven? I would be driving Miss Daisy and the other guy driving at 10/10ths everywhere he goes.

You simply cannot quantify in that sense.

The "split-in-half" test sounds interesting though!!

[magic77]

interesting points I found running on normal shell as good as BP ultimate which caused car to be sluggish and hard work to get going. Normal BP was even worse.

These days its Sainsburys or Shell. Generally as my sainsbiry is always very very busy so fresh fuel and Shell any other time as get best results

Found for best diesel you got to go to europe for some reason they diesel even normal gives better performance and if you get vpower its like another car

[HighlandPete]

The problem is, no two engines will be exactly the same, (tolerance stack) so we don't start from a fixed benchmark. All the companies can do is test to a specific regime. How can they say X, will get Y results, if they do Z?

We know the official fuel testing regime is viewed by many as mis-representative, as A, B or C can't get the results. But what can you do? Test each car and post the exact results? But then again it will only be for a specific test, not the variables.

I'm totally aware there are so many factors here, that we bog down in the detail. I drive a lot of time in high humidity conditions, I'd like to think that by doing what I do for fuel, after extensive research, is the best I can. That I won't have as much muck and gunk in my manifold/EGR valve and around my engine's valves as the guy who uses the cheapest supermarket fuel he can get, and evidence shows, but again mostly by users, that one fuel smokes, another doesn't. Ask many a Golf diesel driver which fuels work in VW diesel engines, particularly for particulate smoke on cold start up.

Deviating to petrol for a moment, you'd think a 286bhp V8 engine would be hardly the example to notice using a premium petrol. But I assure you, put in Shell Optimax, as it was at the time, and my engine became alive, was so sweet and on kick-down the response was at another level. Cruising at the same speed, 3mpg gain was common, required the lightest throttle. Now I couldn't get Optimax locally, but when I could get it, the driving experience was on another level, to standard unleaded petrol.

HighlandPete

[magic77]

Also worth pointing out BMW state no additives in diesels I think there is even a sticker in the fuel cap.

I recall a conversation with a dealer that if you get engine problems and they find addtitives in the fuel it can be used to get out of paying for repairs if they can have a link

[CarAbuser]

I do the same 100 miles journey twice a week and pass a Total, BP, Esso, Sainsbury's and about 3 Shell stations.

Currently I fill up at Shell because I get 1% off using their loyalty card, 1% cashback on my credit card and the Fuelsave is 5p a litre cheaper than the standard BP diesel (130.9 vs 135.9!!).

I have tried VPower with my previous car and noticed a change but it didn't have a trip computer so i could get nothing to prove it.

I will try running my tank down and topping up with Total Excellium(?) and take note of the mpg. It should be fairly conclusive since my route never changes and due to my journeys being later in the evening I usually just have cruise control set the whole way.

[Falmouthboy]

Whilst I have found clear benefits with V Power petrol (but that only works in a car optimized for 98 RON Fuel) as is the case with most petrol BMWs (though I noticed not the 116i courtesy car I had recently where the fuel cap said 95 RON), I have found no benefit in using premium diesel in any of the diesel cars I have tried it in.

The thing is, with pertol, aditives aside, there is a clear 'benchmark' in the fuel's RON and what the car's spec sheet says it's optimized to run on. There is nosuch benchmark for diesel.

[HighlandPete]

Originally Posted by magic77

Also worth pointing out BMW state no additives in diesels I think there is even a sticker in the fuel cap.

One reason I went for the BP Ultimate option, rather than standard BP and an aftermarket additive. Obviously branded fuel 'additive packages' are not what BMW mean by additives.

HighlandPete

[HighlandPete]

Originally Posted by Falmouthboy

The thing is, with pertol, aditives aside, there is a clear 'benchmark' in the fuel's RON and what the car's spec sheet says it's optimized to run on. There is nosuch benchmark for diesel.

There is the argument, that cetane enhancers are beneficial (up to a point, about 55) in high performance diesels, as combustiuon is improved. Basic diesel fuel cetane level (51 -52) is not necessarily high enough for optimum performance.

But all things aren't equal, refurbishing a set of injectors that are not spraying perfectly could be a wiser move than trying to improve the engine with a differernt fuel. Which may not work any better for combustion, in those compromised conditions, than the cheapest you can find.

Essentially a premium fuel is designed to work in optimum conditions and hopefully help an engine keep that way.

BTW, some users are relatively new to diesel motoring, but remember some of us have 30 or more years with diesel combustion and have learned a little.

HighlandPete

[kaishang]

Mmm, how about high speed marine diesel engines like this one (V20 MTU power about 3,000kW) .

These are definitely not low spec; they typically get used in high speed commercial vessels eg cross-channel catamarans or surface warships.

They don't ever use premium diesel due to cost and lack of availablity.

[HighlandPete]

One of the fuel dyno tests was conducted by FifthGear at Thor Racing.

They used a Citroen C5 diesel and a supermarket diesel as the benchmark fuel. They simply drained between fuels and therefore was only maximum bhp tests, not fully benefitting from a 'cleaned' engine.

Supermarket diesel: 155bhp
Shell V-power diesel: 161bhp
BP Ultimate dieseel: 161bhp

They concluded with the comment, that with extended use and in high performance engines, the gains can be more significant.

For me, the bhp gain is only part of the story. Diesel engines typically are best at lower revs and at part load, improved torque comes from the best combustion in that middle range. Where most of us drive, mile after mile.

HighlandPete

[335diesel]

Originally Posted by Dave_3

On the contrary, all the anecedotal comments that seem to back the Oil Companies' claims would suggest otherwise.

If you haven't tried it yourself, you are strongly postulating about something you have no experience of at all. Which isn't a strong poistion to criticise what other have experienced first-hand.

Or perhaps you have tried it - and you are relating your own findings about "what it feels like" - something you dismiss.

Either way ....

D.

I have - several tanks (in a row) of super UL in my R32 - no discernible difference.

A few tanks in my 335d - no difference and much more expense.

I need scientific facts before I'll be parted with any extra money. I have no problem with spending on the car to look after it but only if I feel it's justified.

I'm not saying I'm right on this - just my opinions based on personal experience but also fairly extensive "research."

As with the marine engine example above, also look at the Challenger 2 tank and many other "high performance" diesel applications that run happily on anything.

Let's not forget - our engines are not far removed from those things that plough and fling cow sh1t all over fields.

[dxb335d]

Mine ran nicer on super-denz!

[toxicnerve]

Hang on.

I think it should be noted that there's a difference between "high performance" and just BIG diesel engines. I doubt very much the industrial stuff being eluded to in this post runs at tolerances as tight as those we see in "high performance" road diesels.

I would hazard that the marine diesel above or the Challenger tank engine have injectors that are entirely different to the ones in our cars and I would be willing to bet they are engineered for completely different characteristics (i.e. they will be significantly more reliable than the ones in our cars).

You can't compare those sorts of diesel engines with the ones in our cars. While the basic principles will be the same their engineering will be completely different.

[335diesel]

I'd also argue that a purchaser of a large boat or tank is much harder to fling marketing guff at. But is equally keen to make sure his or her machine runs as well and reliably as our "refined tractors."

High performance diesels are designed to run on diesel - our UK diesel is good stuff with a decent ignition rate. It's in the US and other countries that they have poor quality diesel and need additives (such as urea - tsk tsk) to make them work. We pay a fortune for our fuel but it IS good stuff on the whole and plenty sufficient enough for anything from a diesel Fiesta to a Q7 V12 TDI. Until I see clear evidence that I "need" to use silly fuel, I shall stick the same diesel in my 3.0L twin turbo six as I do in my rather agricultural 2.4L single turbo (almost) Transit based four.

And the same petrol in my boat as I do in my mower and strimmer (the later with two stroke oil added)!

Yet again, it's refreshing not to be completely alone in my opinions!!

[dxb335d]

Fair enough mate. Bet yours feels flat as a pancake.

[toxicnerve]

I'm not taking a side either way, I've always used regular.

I think for the next few tanks I might try some "super" and see if I notice/feel a difference.

Not sure whether to go for V-Power of Ultimate though...

[335diesel]

Originally Posted by dxb335d

Fair enough mate. Bet yours feels flat as a pancake.

Feels exactly the same as it did after a few tanks of "super" diesel. Mine is a standard 335d after all, not a Dragster eXtreme Ballistic edition

Hey we all make our own choices based on facts and what we believe in - after all, it's just about a free country. Well for now anyway.

[dxb335d]

LOL.....

Take more than a few tankfulls mate!

[script]

Mines ballistic on Red diesel