Is Premium Diesel better than Standard Diesel?

[JakeBlade]

Interesting article: http://www.oilem.com/content/146-premium-diesel-versus-standard-diesel-fuel.html

[Salut]

JakeBlade, thanks for the article. I think I am right in suggesting that this topic has appeared in a number of motor forums.

 

I have previously queried the use of different grades with my local (trusted) garage. Their comments suggested that the shorter inner town journeys cause far more problems to the engine management than the grade of fuel will ever do. Hence, every so often we head out for a long "revvy" run round north wales, naturally sticking to the speed limit.

 

Locally the price of fuel tends to dictate which grade I buy. I had a spell using BP Ultimate, at a premium price too! I keep a record of motoring costs and note that during the use of the Ultimate there was only a 2 mpg gain over the supermarket stuff. Currently Shell is very competively priced, so I am using that. What the change internally might be, I hope I will never know.

 

Touching wood to be certain of my next observation, the car has always passed the emissions test for the MOT. Further the garage have never raised any query regarding other consumable components. I have been shown an oil filter that failed to live up to what it said on the tin. I am led to believe that that was due to very poor (cheap) quality oil being used. As the mechanic pointed out then, you cannot skimp on oil.

 

I suspect your posting will draw other comments, both for and against. Still, thanks for the post it helped pass a coffee break!

 

All the best

[mellyboy]

I use standard Diesel with with Millers added probably once a month , if I tow my caravan I stick some Millers in. Is this as good as using the higher grade diesel ?

[JakeBlade]

I use shell fuelsave plus millers in every tank.

[gadgetman]

Moved to general car chat as will interest everyone

[littleade]

I use shell fuelsave plus millers in every tank.

+1 on the above. Costs about 2p a litre extra over standard diesel, which is a considerable saving compared to premium diesel. Pays your money......

http://www.millersoils.co.uk/automotive/tds-automotive.asp?prodsegmentID=227&sector=Car

[slider]

Just a con trick

[hatchy]

Standard fuel here (be that supermarket or branded garage, I'm not particularly fussy) plus 50ml of Millers ecomax in every tank.

[Matt Bodycombe]

I never use premium Diesel anymore as I have never seen any benefits in economy or response from the stuff. Others on here in posts on this subject in the past have sworn blind the benefits so the whole thing is debatable. Guy in my local filling station says that "it has twice the additives" and that you get the benefit if you drive a lot of miles  but somehow I doubt it.

 

As to Millars only trouble with that stuff is that you have to fill the car to the brim to get the correct measurements and I very seldom fill my car right up so have bever bothered with the stuff. I follow advice that I read from that guy Honest John who writes in the telegraph and make sure I give the engine plenty revs through the gears a couple of times a week to blow all the crap through.

[jamiebeveridge]

Ive always found the car to be a bit quieter in tick over with premium and i probably use it 40% of the time the problem for me being that i work at sainsburuy so have to pass our own station without premium 10 times a week. I also use half a bottol of redex every other tank or so. I think i can notice the difference in performance but even if thats debatable id bet alot of money on the fact that both our cars are quieter on premium

[mellyboy]

I never use premium Diesel anymore as I have never seen any benefits in economy or response from the stuff. Others on here in posts on this subject in the past have sworn blind the benefits so the whole thing is debatable. Guy in my local filling station says that "it has twice the additives" and that you get the benefit if you drive a lot of miles  but somehow I doubt it.

 

As to Millars only trouble with that stuff is that you have to fill the car to the brim to get the correct measurements and I very seldom fill my car right up so have bever bothered with the stuff. I follow advice that I read from that guy Honest John who writes in the telegraph and make sure I give the engine plenty revs through the gears a couple of times a week to blow all the crap through.

Is the ratio of Millers to diesel as critical as this post suggests?

[KenONeill]

The OP's link is long on opinion and short on facts regarding citane index (the only thing that will affect combustion from one tank to the next on a given specific engine). What it does say is that there's not enough detergent in "premium diesel" to actually clean an engine.

 

Then it goes on to ignore the fact that a film of carbon on the combustion chamber roof and piston crown is actually desirable since it raises the effective CR, and by acting as an insulator, also raises the BMEP of the engine.

 

"Premium petrol" is a different argument, since it gives a higher octane number and hence allows you to run less ignition advance.

[peanut18]

Not at all, if you read the instructions you can 'double dose' it every now and then. I've been using it in my Transit motorhome recently and I have seen positive results.

[Matt Bodycombe]

Hmmm but why does it say in my car handbook not to use additives on Diesel engines?

[JakeBlade]

My fuel filler lid says "no biodiesel", but unfortunately the ridiculously wide uk diesel spec allows an ever-increasing proportion of biodiesel in the blend.

[Matt Bodycombe]

Think most Diesel has some biofuel in it now but always thought was limited to about 5% :/

[JakeBlade]

It was, but in 2009 the max amount of permitted biodiesel was increased from 5%, to 7%.

[cheezemonkhai]

My standard reply of......

BS EN590

Edited 13 February, 2014 by cheezemonkhai

[KenONeill]

My standard reply of......

BS EN590

Serious question - Is that a prescriptive standard, or a minimum specification standard?

[Gwilo]

I think the premium stuff is negligibly 'better' than the average supermarket stuff, but 'better' is subjective.

Do I get better MPG?  Marginally.

Do I get better engine response/less noise? Yes.

Do I have cleaner, better maintained engine internals?  who knows.

Do I have a bigger dent in my wallet?  most Definitely.

 

Is it worth the trade off?  Not really.

 

I filled up with tesco's diesel yesterday (as I was almost sucking on fumes & morrisons was all shut up due to storms) and was instantly struck by how much quieter the engine sounded from inside the car on the throttle.  I've also seen better consumption (up 4mpg each way on my daily commute) for a miniscule uplift in price.....

to be honest, I think if the price at the pumps was balanced out more by a generous reward scheme, I would use Shell all the time.  the only reason I use Morrisons is because every two/three months I get a fiver off food shopping.  But maybe if I use Clubcard points, I can get a reduced prices tablety thing.....

[justinlok]

I never use premium Diesel anymore as I have never seen any benefits in economy or response from the stuff. Others on here in posts on this subject in the past have sworn blind the benefits so the whole thing is debatable. Guy in my local filling station says that "it has twice the additives" and that you get the benefit if you drive a lot of miles  but somehow I doubt it.

 

As to Millars only trouble with that stuff is that you have to fill the car to the brim to get the correct measurements and I very seldom fill my car right up so have bever bothered with the stuff. I follow advice that I read from that guy Honest John who writes in the telegraph and make sure I give the engine plenty revs through the gears a couple of times a week to blow all the crap through.

 

Matt - would have to agree with you.

 

When I ran my Octi vRS, I never found a noticeable difference when I filled up with BP Ultimate apart from a huge price difference. And I did drive a reasonable mileage every day.

 

IMHO - Don't bother with premium diesel. After all, you are driving a diesel car not some high performance V8 petrol that is designed to run on premium fuel (and for people who don't really care about the cost of the fuel)!!!!!

 

J

[Chan110]

Depends.

From experience (and this could just be me),

I only put in premium fuel if they were Jap or higher performance cars.

Certainly Lexus and Scooby were quieter and more consistent delivery of power with Shell VPower.

And my BMW better delivery of power.

I found no difference for most european brands.

As for the EXTRA MPG thy claimed - thy withdrew that claim now - lol

Having said that, i only use Shell normal fuel.

And rare ocassions at supermarket - just to mix it a little ...

[cheezemonkhai]

Serious question - Is that a prescriptive standard, or a minimum specification standard?

 

http://en.wikipedia.org/wiki/EN_590

[JakeBlade]

A high cetane rating generally leads to a cleaner and easier combustion.  You will notice the effects more in a PD engine, than in CR - as audibly less "clatter".

 

EN 590 is a minimum specification, and so there is scope for differentiation between fuels from different providers.  A higher bio-diesel content to the diesel will have higher NOx in the exhaust than a diesel fuel with lower bio-diesel content.  Something to watch out for if your car is close to the limit on the emissions test at MOT.

 

Bio-diesel also has a lower calorific value than "normal" diesel.  So a higher %age bio-diesel in the blend will lead to lower energy content in the fuel = lower mpg.

 

Or at least that is the theory anyway...

[Ootohere]

There are Diesel Engines that the Fuel put in makes not a bit of difference, like ones that will run on Used Vegetable Oil, or New Vegetable Oil, Burst Oil and the likes.

 

Obviously there are Modern and technically advanced engines that need fuel that is to a standard, and can benefit from a better standard.

Those that only run on the more expensive and heavily taxed product.

 

But basically, they are Diesels, they need Fuel & Air and once they are fired up and generating heat/Compression they run.

Just Heavy oil Burners or as some consider Dirty Diesels.

 

If fuel to run costs 50% less, then some could not care if it needs 25% more fuel to run it.