Premium Diesel Long Term Test

[J.R.]

You saved me from replying Rootemoot.

 

I think the TDi's may indeed have a knock sensor which initiates a torque limitation, one of the parameters that can be monitored in VCDS, would have to read the self study guide again to be sure.

[Ootohere]

What makes a difference is an efficient / smooth running petrol or diesel can get better fuel economy if it gets going quicker, 

if the engine gets up to temp quicker, 

the oil used can help with that as well. 

 

Hense VW have gone VW508 / 509.  0w 20 FS IV, 

Who cares about engine longivity!  Not VW.

[MarkyG82]

9 minutes ago, TDIum said:

 

Ok, but to the casual reader, it may seem that the 5% increase is a reasonable assumption, and not just a made up number for a made up phenomenon. 

 

 

Made up number, yes.  Made up phenomenon, not necessarily.  I will need to check my numbers but I'm pretty sure I have seen an increase in consumption using regular fuel. Particularly on the occasion of filling up one tank away from any sources of premium an seeing a dip in economy.  Although this could well be a coincidence due the many factors listed above.  Saying it is a "made up phenomenon" is not a fair statement as many people have stated they see an increase in economy.  

[Russ77]

I've been driving for just over 24 years.  My Octavia is only the 4th  car I've owned in that time and my second diesel, up until last September I've pretty much run exclusively on supermarket fuel seeing no adverse impact of doing so.

 

However, one of my good friends is a mechanic and had said he was seeing an increase in issues with diesels that are being run on supermarket fuel.  I've always taken such observations as anecdotal but seeing as there was only about 4p-5p difference in my local Asda and local BP station I thought I'd run BP diesel (only standard as they don't have ultimate).

 

I bought the car in Feb 2017 just as the "beast from the east" hit (just my luck).  I'll exclude the first fill-up as I was looking for any excuse to go out for a drive but the remaining fill-ups between March & September when I switched fuels, the average MPG was 53.2 BUT that included a very sedate 200 mile drive from Essex to Wales where we had to stick to 50MPH due to road restrictions and bad weather, the MPG was 52.05

 

The same period this year 54.34MPG so we're talking 1.2 - 2.15 MPG difference.  Whether that's due to using BP fuel or not's another matter.  My gut feel is that some major roadworks were completed earlier this year which shaved a consistent 5-10 minutes of my homeward commute.  I used to be lucky to get an indicated 50MPG while there were roadworks, now it's a more consistent 55MPG+.

I'd definitely be interested to see if there is any difference using the Ultimate fuel

[Ootohere]

March and the Winter Diesel is used up in UK Filling station tanks and the Spring Formulation gets delivered.

Some cars might sit with winter diesel in if not being driven, 

some used cars at Dealers / Traders might have last years Summer Diesel still in.

[ScoutCJB]

3 hours ago, RobGy said:

 

That's what this is intended to be a long term real life experience, but this thread will become a semi-structured record (largely for my own purposes, but if there is someone nerdy enough to find it useful then great) of my completely non scientific observations.  I will report on both OBC and brim to brim.

 

Someone asked what am I expecting to see.... not much other than my wallet get thinner faster!  But let's see.  Some claim the engine runs smoother, less DPF regens, better consumption.  Others say it's snake oil.  I have very few preconceptions.

 

Im not aware that my Oct 2 Scout ever did regens apart from once when I got a dash error after2 hrs of stop start around London.  I had to sit at 55mph ish in 5th for 10 mins then cleared an never came back.

 

With the Oct 3 im not really aware that it doing anything other than regens.  I would say it regens every 350 miles ish regardless of whetehr thats cross country or motorway driving.  Rule of thumb, based on my commute to work which if i go to the office is the same time, same speeds etc is 47mpg when it regens and 55 mpg when it doesnt.  If I cough at the accelerator and time gear changes, dont fart so i can keep windows closed and turn fans off etc is 62mpg

[TDIum]

25 minutes ago, MarkyG82 said:

  Saying it is a "made up phenomenon" is not a fair statement as many people have stated they see an increase in economy.  

 

Many people claim to have seen the Loch Ness monster, but few would dare to compare her length in summer and winter. As for guessing her weight - that would surely be ungentlemanly. 

Edited 7 October, 2019 by TDIum

[BionicJohn]

My best fuel (diesel) consumption figures have been with Tesco cooking and long drives (on Carrefour's) across France and Spain, but perhaps that's to be expected with warm weather and quick warm-ups.

 

As for premium fuels, it's arguable if the additional additives are worth the best part of 10p/litre.  I worked in the oil additive industry some time ago and the lab boys were always sceptical about the value of the additional higher spec detergents, anti-corrosives, anti-acids and octane/cetane enhancers.  They argued that frequently changed high quality fuel filters are better value.

 

Supermarket fuel nearly always get bad press but I've never met anyone who would phone up trading standards to complain.   Considering supermarkets supply about two thirds of cars' fuel, I only know of one incident (please correct me if I'm wrong) when dozens of cars conked out because of the fuel - and that turned out to be contamination at the refinery rather than anything inherent in the place of distribution.

 

Most of the fuel comes from the giant supplier Greenergy who sell around 20,000,000 litres a day in the UK.

Edited 7 October, 2019 by BionicJohn

[Gabbo]

I will still stand by my belief that the driver will make a factor of 10 difference to fuel economy compared to supermarket vs premium fuels (where I would sit on the "there is no difference" side of the fence).

Adapting your driving style, to avoid unnecessary acceleration/heavy braking & manage a constant cruise on a motorway/dual carriageway (instead of being constant on/off the accelerator pedal) will give you a much bigger return in your wallet than shell vs ASDA in my view.

although, I do appreciate this is not always easy to do in the heavy traffic in the UK..! 😀

[MarkyG82]

51 minutes ago, TDIum said:

 

Many people claim to have seen the Loch Ness monster, but few would dare to compare her length in summer and winter. As for guessing her weight - that would surely be ungentlemanly. 

 

Humorous.  However, it is not relevant to what could be a genuine technical discussion.  The evidence I have seen so far shows that using premium diesel offers a slight increase in economy.  Whether this is down to the burning of the fuel alone or keeping the fuel system in check (which in turn will provide a better burn) doesn't bother me.  All I know is my engine benefits from it.  

[ChoonDoode]

the additives, surely, must aid in keeping the engine burning the fuel efficiently. Or is that me buying into the blurb?

[TDIum]

Additives are great, that is what you pay the extra for. Also having for example no bio-ethanol in your unleaded. 

Edited 7 October, 2019 by TDIum

[Ootohere]

Best thing is that the OP is comparing the Derv or more expensive Derv which is called Premium in a 5 year old 1.6TDI.

Almost as interesting as comparing a Before the Fix and after the Fix.

 

@RobGy

Has your car had the VW Emissions fix so new engine management and a flow device fitted in the air intake?

[TheWanderer]

I brimmed the tank of my RS which is now behaving impeccably added a shot of Miller's Eco Max for petrol and did 400 miles on it with 40 miles still available showing up on the VC. 

 

Quite impressed by that with many A  trunk roads and motorway miles done. I must admit that I wasn't expecting to get that sort of distance out of a tank of fuel.

[Ootohere]

Just as well you never filled with diesel though.

[RobGy]

1 hour ago, Roottootemoot said:

Best thing is that the OP is comparing the Derv or more expensive Derv which is called Premium in a 5 year old 1.6TDI.

Almost as interesting as comparing a Before the Fix and after the Fix.

 

@RobGy

Has your car had the VW Emissions fix so new engine management and a flow device fitted in the air intake?

Yeah, I know, it's not a performance vehicle but its one I intend to keep for the long haul, and reducing maintenance costs and improving performance and efficiency are important to me.  I presume it has had the fix, as there are no outstanding recalls on the vehicle.

 

2 hours ago, Gabbo said:

I will still stand by my belief that the driver will make a factor of 10 difference to fuel economy compared to supermarket vs premium fuels (where I would sit on the "there is no difference" side of the fence).

Adapting your driving style, to avoid unnecessary acceleration/heavy braking & manage a constant cruise on a motorway/dual carriageway (instead of being constant on/off the accelerator pedal) will give you a much bigger return in your wallet than shell vs ASDA in my view.

although, I do appreciate this is not always easy to do in the heavy traffic in the UK..! 😀

I am a bit of a hypermiler except in times when getting home asap is the priority.  This test is about whether I can get that little bit extra - and make my car run better and last longer - by using "decent" fuels, or whether it's all a big con.  I've been a supermarket / Costco fan for years but I'm intrigued to see if there is any difference to be seen.

[Ootohere]

@RobGy

If the car is not still covered under the Skoda / VW Trust building guarantee for 24 months it can be worth having 'The fix' rolled back and a remap if the car is a keeper.

Then again let sleeoing dogs lay if it behaves OK, has OK economy and there is no EGR issues.

[TheWanderer]

50 minutes ago, Roottootemoot said:

Just as well you never filled with diesel though.

 

Nearly done it a few years ago. 😳

[RobGy]

So, unscientific as it is to post this so soon, here's an update:

Day off yesterday and all my driving was tons of stop start city traffic yesterday which dragged me down to high 40s mpg.

Drove it gently to work, did a fair bit of driving round town and the DPF regen kicked in.  Then a short countryside stint before giving it a good thrash on the dual carriageway on the way home before a lot of heavy traffic in the last few miles.  54mpg since refuel now.

 

Part of this test is also to test the overall economy of the car in two ways - what's the best I can get out of it driving like a saint, and what's the economy like when I drive it a bit more...briskly.  There's a reason I joined this forum after all

[Ootohere]

@RobGy

Are you not zeroing then at the start of each trip.

 

Long term test that interests me is a brommed tank and how many miles covered with any fuel and how many litres to brim.

Tank fill after tank fill over the weeks, months and year.

[RobGy]

12 hours ago, Roottootemoot said:

@RobGy

Are you not zeroing then at the start of each trip.

 

Long term test that interests me is a brommed tank and how many miles covered with any fuel and how many litres to brim.

Tank fill after tank fill over the weeks, months and year.

Yes, I am monitoring four things:

OBC "Since Start" - basically, from cold start, gives me an approximation of my commute mpg which is important as it forms 9K miles a year

OBC "Since Refuel" - checking this against...

Brim to brim calculations (done one so far and OBC was 2-3mpg over optimistic)

OBC "Long Term" - undecided as to when this will be reset.  A long time.

 

As stated above, any ongoing updates are totally unscientific and for my own records / interest purposes only, but may form some part of the long term analysis as I can look back at time of year, type of driving etc. to get an idea of environmental factors involved.

 

54mpg for city driving makes the Octy by far the most economical car I've ever owned.  Second was a Fabia, which did great motorway economy (60s if I drove like a saint) but poor city (40-45 on my commute), third was a Kia Ceed, 55/40-45 respectively.

 

I would like to get the city mpg up to 60 as a longer term average.  I am keen to see what it will do on a motorway, but life commitments are getting in the way of a road trip.  Looking at a weekend in Northumberland / Scotland to give it a good run in the next month or so.  I will do one leg of the journey at eco speeds, the other leg at 70.

[Ootohere]

Check actual distances with GPS if really fussed.

Your car is likely on tyres that are not new so at maximum size, so the Mileometer is not accurate, but maybe 1 mile per 100 off.

Maybe your car is not on the same tyres, maybe you will fit winters, adjust the pressures as the weather changes.

 

Having done  years of hypermiling when getting different cars and know all the various things that affect the MPG then just driving without hypermiling

you get an idea just what is what.

Then having others drive your cars and seeing their MPG can be revealing.

 

In the end Brim to Brim is really all that matters, then what you put in the car and carry about, 

and if your journeys are with tail winds, head winds, cross winds, cold. rainy. snowy.

 

I know the MPG of every vehicle i have ever owned / driven regularly since i legally started riding / driving, because i ride / drive the same roads, 

only difference from then to now is Average Speed Cameras / Camera Vans and Speeding tickets.

Edited 9 October, 2019 by Roottootemoot

[cheezemonkhai]

On 07/10/2019 at 17:07, TDIum said:

Additives are great, that is what you pay the extra for. Also having for example no bio-ethanol in your unleaded. 

 

All fuels require biofuel in them, so I don’t know where you got that bit from.

[Ootohere]

I filled up last week at a Morrisons and there were new Pumps not just new stickers, 

and the Diesel showed B7  & the Unleaded 95 E5,

as pumps will all be showing in the UK come time so that no Bio confusion for those from overseas or even people that live here and fill up regularly or iregularly.

[wyx087]

49 minutes ago, cheezemonkhai said:

 

All fuels require biofuel in them, so I don’t know where you got that bit from.

Having not visited a petrol station for over a month, I looked up B7 wondering what it was. This article says "though no such requirements are in place for super-unleaded."

https://www.autoexpress.co.uk/car-news/106137/official-e5-petrol-and-b7-diesel-fuel-pump-labels-introduced-on-uk-forecourts

 

E10 sounds great, allowing 2% reduction in CO2 without motorists lifting a finger. I do hope they bring this in sooner.

 

Found the official government campaign page: https://knowyourfuel.campaign.gov.uk/

Quote

Last year, blending renewable fuels in this way reduced CO₂ emissions by the equivalent of taking over 1 million cars off the road.

Nice!

Edited 9 October, 2019 by wyx087