‘Premium’ diesel

[TheRivieraKid]

Hi all, my newly acquired 1.6TDI cr Monte Carlo should be arriving in a couple of hours, and it got me thinking about it’s first fill up.

 

I know that with petrol cars the so called premium fuels have a higher octane rating, where with diesel it’s more to do with additives that keep things clean, have I got that right?

 

I’m just wondering what everyone’s thoughts on this are?  Is it worthwhile using the more expensive diesel, all the time, every other fillup, once a month, not at all?

[AMD87]

I’ve ran mine religiously on vpower since I picked it up and I’ve never had an issue with it. 

[26DIPP]

The short answer is "NO".

 

Many bodies / organisations have compared different diesels - cheap supermarket vs. "premium" - and they all come up with similar results. No more power when tested on rolling road. No better fuel consumption in real world tests. No better engine protection.

There are only a handful of refineries in the UK and everybody buys from them.

You will subsidize the companies by using the premium stuff.

[Ootohere]

How many refineries or cracking plants there are in the UK has nothing to do with it as Royal Dutch Shell or Greenergy can be bringing in base fuels from anyplace in the world. https://www.greenergy.com/uk

Then the additive packages are added a depots.

 

The cleaning / detergents might make a difference to cleaning a carboned up engine or not.

Might reduce the emissions, which is all that many claim.

 

I have seen the Super Unleaded various tests that Fifth Gear have done and others.

As to the tests on Diesel in the UK not so.

*Do your own.*

 

For Premium Diesel from ESSO, BP, Shell or anyplace else it is dead easy, you have the car, you buy the fuel, so just try the regular Derv or the Premium Heavy Oil with more additives than the basic and see yourself.

 

Just look at the Cetane rating for Regular or Premium Diesel where you are buying it and see if there is a difference.

 

This is not like the octane (or Mon elsewhere )  of Unleaded petrol at 95, or 95 Minimum, and Super in the UK at 97 ron minimum or 99 ron minimum. (No longer is 98 ron min sold in the UK.)

Edited 9 June, 2020 by Roottootemblowinootsoot

[Bertie90]

i personally think it makes little to no difference, for about 2 years I ran BP ultimate and Shell V+. I did get a few mpg's more than Saynsbury's own. I still got injector failure and my intake manifold was still caked up with soot. Switched to sainsbury's and I'm noticing 0 difference apart from my wallet.

 

Save your money and spend it on extra oil changes and high quality parts.

[Schtum]

It definitely does make a difference in my remapped Golf. It runs best on Esso premium diesel when I can get it and then on Shell V-Power which is what I usually use.  On supermarket diesel it can misfire when driven hard. 

[Ootohere]

@Schtum  If it misfires on Diesel from Asda, Tesco, Sainsbury's, Costco then it must just be the same on anyone's  Regular Diesel from Esso, BP, Gulf, Shell, Texaco or other filling stations as diesel is diesel, the Supermarkets buy in the same diesel when not getting Premium Diesel.

 

If bought in Scotland the diesel came from Grangemouth or a Greenergy depot almost certainly.

Edited 10 June, 2020 by Roottootemblowinootsoot

[eccleshill]

I am an MPG geek!

Here are some of my "real world" figures.  I give my 1.6Tdi the occasional few fills of premium diesel on the basis that it won't harm anything but my wallet and it may help keep things clean.  I have done 67k miles from new.  52k miles on standard diesel at 54.1mpg and 15k miles on premium at 55.5mpg.  All data is from brim-to-brim not from the trip computer.  Now clearly I don't completely drain the tank between fills so there will always be around 10 litres of t'other type of fuel when I fill up.  I usually fill up when the gauge drops below 1/4 so in general my fill-ups are 45-52 litres into a "55" litre tank that I reckon holds 58 litres at a squeeze.

Can't say I've noticed any performance difference and DPF regeneration is every 200-350 miles irrespective of fuel.  Oh, and my car has NOT had the dreaded emissions "fix".

 

Caveat!

Whenever you do fuel comparisons you have to be very careful of unconscious bias causing skew of results.  One such could be "I've paid an extra £8 for that fill of premium to see if I get better MPG and/or better performance"  and then subconsciously drive that little bit more gently to prove your point and convince yourself that the engine really is running quieter and smoother than it does on that supermarket crap.  You know, the same as people taking a rat-run short cut always drive that bit faster to prove their route really is quicker!  That is why the pro's do blind testing!  It may also contribute to the extra 1.4 mpg I get from premium fuel.

 

[mrgf]

2 hours ago, eccleshill said:

 

 

Caveat!

Whenever you do fuel comparisons you have to be very careful of unconscious bias causing skew of results.  One such could be "I've paid an extra £8 for that fill of premium to see if I get better MPG and/or better performance"  and then subconsciously drive that little bit more gently to prove your point and convince yourself that the engine really is running quieter and smoother than it does on that supermarket crap.  You know, the same as people taking a rat-run short cut always drive that bit faster to prove their route really is quicker!  That is why the pro's do blind testing!  It may also contribute to the extra 1.4 mpg I get from premium fuel.

 

As might a loosened-up engine!

I dont wanna pi55 in your pool, but the extra MPG may just be due to loosening-up of the engine as it covers more miles. I have read and heard many times, particularly with diesel's, that they become more fuel efficient after a decent running-in period. At 50,000 miles, I would fully expect the vehicle to run smoother and drink a little less then when new, assuming of course, service schedules had been adhered too! With such a small deviation in your fuel calculations, this could have been down to many other factors anyway. New, different pattern tyres, different loading of the vehicle, a/c usage, etc could have all taken a part. You suggest you now get somewhere around 1.4 MPG extra from the premium fuel. at around ten gallons a tank, thats an extra 14 miles per tank. I am reckoning you pay an extra £4 a tankful so the benefit has been outweighed, even if it was only a fuel factor that changed. If you went back to the usual stuff and the MPG dropped back down again, to what you started with, that would say a lot more about the figures. 

 

I have never bother with premium fuels, except when I have pulled up to the wrong pump, that only has it and either there is a queue or I can't be bothered to swap pumps.  When I did use it, I felt no difference in the drivability or fuel consumption but then again, have never done it for more then a tank or two at any given time. Instead, I use Cataclean Diesel, after reading a revue on it from the RAC, which was in a driving school publication, for driving instructors. I pop this in a few times a year and particularly prior to the MOT. The RAC stated they carry and recommend using it as an endorsement.

 

Others will say its rubbish or favour a different brand but then, thats the whole point of opinions. 

So, Mr Riviera,  my recommendation is keep using standard fuel and slap in some Cataclean Diesel every three months or so. Usually, you can get a good deal on the "Bay" Where two bottles cost around £23. That will be more economical then the premium fuels, whilst adding something you know will help clean up the emissions and fuel system, to some degree. 

[eccleshill]

1 hour ago, mrgf said:

 

As might a loosened-up engine!

I dont wanna pi55 in your pool, but the extra MPG may just be due to loosening-up of the engine as it covers more miles. I have read and heard many times, particularly with diesel's, that they become more fuel efficient after a decent running-in period. At 50,000 miles, I would fully expect the vehicle to run smoother and drink a little less then when new, assuming of course, service schedules had been adhered too! With such a small deviation in your fuel calculations, this could have been down to many other factors anyway. New, different pattern tyres, different loading of the vehicle, a/c usage, etc could have all taken a part. You suggest you now get somewhere around 1.4 MPG extra from the premium fuel. at around ten gallons a tank, thats an extra 14 miles per tank. I am reckoning you pay an extra £4 a tankful so the benefit has been outweighed, even if it was only a fuel factor that changed. If you went back to the usual stuff and the MPG dropped back down again, to what you started with, that would say a lot more about the figures. 

 

I have never bother with premium fuels, except when I have pulled up to the wrong pump, that only has it and either there is a queue or I can't be bothered to swap pumps.  When I did use it, I felt no difference in the drivability or fuel consumption but then again, have never done it for more then a tank or two at any given time. Instead, I use Cataclean Diesel, after reading a revue on it from the RAC, which was in a driving school publication, for driving instructors. I pop this in a few times a year and particularly prior to the MOT. The RAC stated they carry and recommend using it as an endorsement.

 

Others will say its rubbish or favour a different brand but then, thats the whole point of opinions. 

So, Mr Riviera,  my recommendation is keep using standard fuel and slap in some Cataclean Diesel every three months or so. Usually, you can get a good deal on the "Bay" Where two bottles cost around £23. That will be more economical then the premium fuels, whilst adding something you know will help clean up the emissions and fuel system, to some degree. 

You have completely misunderstood my post.  I am most certainly not advocating the 100% use of premium diesel.  The 52k on standard and the 15k on premium were NOT consecutive.  Occasional fills of premium, 2 or 3 at a time, have been spread across the whole 67k.  That rules out engine loosening up as a reason for the slightly improved mpg, that I fully agree does not alone justify the extra cost.  An unknown factor is how much the cleaning effect of periodic fills of premium have on the subsequent fills of standard so the effect could be greater.   And as I said in my caveat, I also can't rule out driving that little bit more economically when I had a tank of Premium.

 

Your bottles of Cataclean at £23 a pair?  Add a bottle every 3 months or so?  You are spending much more on your engine cleaner than I do, and I have a a strong indication that I get a partial payback on my expenditure.  Also, in my user manual Skoda recommend that you do not use fuel additives...

As you say, You pays your money and you takes your choice!

 

[mrgf]

Point taken. Although, at 11 and a half quid a bottle, that would be around 3 fills of premium. I did slightly exaggerate the frequency of the Cataclean, based I think, on recommendation but the average motorist would most likely only need it twice a year. (As I said I do)!

 

As for the use and mileage figures you gave, the post does make it sound like you did the first 52K section on normal, the second 15K on premium. It reads like you did 52K, then switched to premium, rather then swapped ad-hoc, so to speak. Obviousely thats MY interpretation on it but I would think many would read it that way. Its like reading a text and not knowing the state of mind of the writer, wether they are being sarky, angry, jokey, etc whereas a phone call usually shows this up, if you see what I mean.

I actually re-calculated my figure, too of fuel usage. At around 55L a tank, 10p per L extra cost for premium, thats £5.50 per tank of fuel. A tank of fuel a week will add around £66 to the cost over three months. That is based on main depot fuel prices... Go to say, Asda for your diesel and you will chop off another 10p per L

So, on fairly high mileage, saving £130-odd quid in three months, spending under £12 still saves over a hundred quid on fuel costs! Of course, I don't drive that much every week and nor do many but others will drive more, some by much more. The premium fuel's premium price will escalate greatly, depending on use. I would severely doubt the Cataclean will be needed MORE then four times a year. 

[KeithCheetham]

On 09/06/2020 at 17:30, TheRivieraKid said:

I know that with petrol cars the so called premium fuels have a higher octane rating, where with diesel it’s more to do with additives that keep things clean, have I got that right?

 

 In a diesel "super/premium" is to do with cetane rating - the speed of the burn. If the additives are just a cleaner, the economy should stay the same when returning back to standard diesel from super as the cleaning would have been carried out. Look up 2-EHN, and with that I will retire before Sepulchrave comes along.

 

https://www.jct600.co.uk/blog/fuel-types-explained/

[eccleshill]

3 hours ago, mrgf said:

 

I actually re-calculated my figure, too of fuel usage. At around 55L a tank, 10p per L extra cost for premium, thats £5.50 per tank of fuel. A tank of fuel a week will add around £66 to the cost over three months. That is based on main depot fuel prices... Go to say, Asda for your diesel and you will chop off another 10p per L

So, on fairly high mileage, saving £130-odd quid in three months, spending under £12 still saves over a hundred quid on fuel costs! Of course, I don't drive that much every week and nor do many but others will drive more, some by much more. The premium fuel's premium price will escalate greatly, depending on use. I would severely doubt the Cataclean will be needed MORE then four times a year. 

Your cost calculation is way off the mark.  I use nowhere near a tankful per week!  A tankful per week would take me over 30k miles per year!   I do 9k miles per year.  At an average of 54.5mpg  I use 750 litres of fuel per year.  Around 20% or 150 litres of that is Premium.  My records show an average price per litre of £1.21 for standard and £1.38 for premium over the last 7 years.  That difference of 17p per litre is a cost of £25.50  per year.  That cost reduces slightly because I get a small payback through marginally better MPG when using premium fuel.  Even without the payback it is less than the cost of 2 bottles of Cataclean.

Key thing though: does it do the job?  I've had the car from new for 7 years, done 67k miles, never seen the DPF warning light come on in anger and have passed every MOT.  In addition, over the first 3 years I didn't risk voiding my warranty by using fuel additives against the manufacturers recommendation.

All that said, the best way to keep a diesel engine running sweet is to warm it up then drive like you rented it for 20-30 miles every month or so.   I do that as well!

[Bertie90]

man such a controversial debate. Damn snake oil!!!!

[shyVRS245]

All you need to know is it goes harder and longer. Bit like Viagra for your engine.😄

[dervdave]

Shell V-Power is the best diesel you can buy 👍

[SuperbTWM]

I think anybody that buys premium diesel is doing it on nothing other than good faith that it is better rather than any factual information.

 

As for testing, its impossible to get repeatable results so it would have to be over a very very long time. My commute is as consistent as it could possibly get in terms of a constant speed with no traffic but even then, it might be windy one week and I could average 52mpg and the next its nice and warm with no wind and I average 64mpg. Its a complete lottery. Its the same with the cleaning aspect, unless you pull apart 2 of the same engines, driven the same way, over hundreds of miles, there is no definitive answer on whether its worth it.

 

 

[Bertie90]

just ask someone else to fill the car up for you with different fuel and do a blindfold test. if you can notice the difference then there's your answer.

[TheRivieraKid]

28 minutes ago, Bertie90 said:

just ask someone else to fill the car up for you with different fuel and do a blindfold test. if you can notice the difference then there's your answer.

Given my reason for asking the question was related to its engine cleaning properties....I don’t think I need a blindfold 😂

 

Point taken for performance/mpg differences though 🙂

[Bertie90]

the only thing it will ever possibly clean is your fuel system, that's it.

[Ootohere]

@dervdave

What is it that makes Royal Dutch Shell premium diesel as sold in the UK better than other Wholeseler / Retailers Premium Diesel?

?

Are you a fuel tester or in someway involved in the production of road fuels?

 

Maybe something for people with the relevant newer engines and buying these fuels.

Maybe not something that need concern anyone with a Euro 5 TDI Defeat Device installed to cheat testing special.

 

 

 

 

Edited 11 June, 2020 by Roottootemblowinootsoot

[mrgf]

I like the theory, Eccleshill. The mileage you do though, is quite low. Based on that, I recon you'd only slip ONE bottle of Cataclean (Or sim) into your tank. That will then cost half your quoted cost of premium over standard. That said, with such low mileage, perhaps the costing is irrelevant to you! The stuff is, after all, just a cleaner but it's claims are supposedly provable or at least as provable as the big forecourts claims to their premium fuel. Performance gain? Go for it... Better MPG? Go for it. Preventative cleansing? Swings and roundabouts!

 

 

The truth about premium diesel fuel | Auto Expert John Cadogan              On youtube, might be worth a look!

Edited 11 June, 2020 by mrgf

[Ootohere]

@mrgf

I never bothered linking that video since fuel as in Diesel and Gasoline is different specs from in Europe / UK.

and he is also talking Winter Spec which we have October to March, but again different spec.

But people might as well see what they think.

 

BP Ads were very different in Australia from those they ran in the UK.