Diesel

Discussion in 'Lounge' started by johne, Sep 17, 2025.

  1. johne

    johne Standing on the shoulders of dwarves.

    Jan 16, 2020
    2,379
    1,000
    Where the Wolds meet the sea
    No, not Diesel engined bikes. I've got a Diesel engined car, and tbh I always fill it up with the cheapest Diesel I can find (not red I hasten to add) . My ten year old BMW 320 is pretty good on fuel, I can get 60 mpg on a run, but I was wondering if the fancy Diesel that some forecourts offer full of detergents or whatever to keep your engine clean (if that's really possible with a Diesel with all the EGR valves and other paraphernalia to reduce emissions) is worth the extra cost per litre? So what do all you guys and gals who run Diesels think? Have you tried it? Do you get better mpg or perhaps a noticeable increase in performance or is it (in your opinion) just another sales gimmick to relieve us of even more of our hard earned spondulies?,
     
    • Useful Useful x 1
  2. Mrs Visor

    Mrs Visor Elite Member

    Aug 21, 2021
    4,027
    800
    UK
    My place of work thinks that the fancy stuff is so expensive that, should you fill a vehicle with it (even by accident), you have to pay for it out of your own pocket :p.
     
    • Funny Funny x 2
    • Agree Agree x 1
  3. Pegscraper

    Pegscraper Elite Member

    Jun 12, 2020
    3,641
    800
    Yorkshire
    I’ve used “super diesel” in the past and not noticed any difference but mine is 28yr old with no emissions crap on it and runs fine on the cheap stuff. General running round I get 25-26mpg on the cheap or the dear stuff so no incentive there. I also run Dipetane treatment, more for injector pump protection from the low sulphur diesel now in use than anything else.
     
    • Agree Agree x 1
  4. MightyBoosh

    MightyBoosh Senior Member

    Mar 29, 2023
    512
    243
    Uk
    I periodically use a bottle of Forte injector cleaner and fuel additive which l think benefits the engine. But changing the fuel filter regularly is the best thing ;)
     
    • Agree Agree x 1
  5. Pegscraper

    Pegscraper Elite Member

    Jun 12, 2020
    3,641
    800
    Yorkshire
    Diesels, especially older ones, used for general runaround and town work benefit from an Italian tune now and again to work the engine hard and get it up to full operating temperature. Regular oil changes also more important on older stuff.
    The basic engine design on my SUV is over 30 yrs old so quite a dirty engine compared to modern stuff. I can’t remember what the actual emission figures are but I think it’s around 2-3 Polar Bears per tank.:p
     
    • Funny Funny x 2
    • Agree Agree x 1
  6. sprintdave

    sprintdave Nurse, think it's time for his medications.
    Subscriber

    May 25, 2014
    1,669
    750
    Birmingham
    My car is a 2009 Peugeot diesel I've had since 2012 and I fill up at the supermarket, usually Tesco. Every 2nd fill up I add a shot of Millers Ecomax, as I only do short runs in the car generally, I give it a good blast now and then. It has taken us to France twice and both times I have managed 800 miles to the tank, brimming before getting on the eurotrain and then filling when almost home. My car is also serviced every year, all filters changed so for me supermarket diesel cannot be too bad. The bike however only gets Shell V Power as it is E5 so no supermarket for that.
     
    • Agree Agree x 2
  7. Armando Morales

    Armando Morales Noble Member

    Mar 29, 2021
    1,077
    443
    Mexico
    2016 VW TDI with the particulate filter and other gizmos for pollution control.
    It is sensitive to diesel quality, I always try to fill it with the best diesel around.
    With lower quality diesel it becomes sluggish and the exhaust filter cleaning routine runs more often.

    On the highway at a steady 120kmh I can get similar fuel economy than on my R1300gs

    I do not use it much anymore, oil changes are being done by time, not by mileage. it is not been driven more than 7500kms per year. Also replace the fuel filter on every oil change.
     
    • Agree Agree x 1
  8. JackWS

    JackWS Member

    Jul 23, 2025
    58
    18
    Scottish Highlands
    I've never put premium diesel in any oil burner I've owned and never even gave it a thought. I run one of the older 2.2 Range Rover Evoque's and it gets all sorts thrown at it, a show pony it ain't. A and B roads, with excursions up to windfarm sites around the 2500 foot elevation. It gets beasted.
    Never had a DPF or injector issue, just tyres and cheap diesel thrown at it.
    Petrol - premium fuel every time in the bike and Audi.
     
    • Like Like x 2
    • Agree Agree x 2
  9. Munchen

    Munchen Well-Known Member

    Oct 1, 2018
    142
    83
    Germany
    Unless I am mistaken, the good fuel has a higher cetane rating than the normal stuff. I was told about 2-Ethyl-Hexyl Nitrate as few years ago and bought a bit of it, still have half a litre actually.
    If it really is the main difference between the two fuel options, you can chuck a really tiny bit in to the tank when you fill up with the normal fuel. It's only about 50ml iirc and it works out a lot cheaper than premium fuel in the long run.

    https://www.powerenhancer.co.uk/pro...99-pure-2-ethyl-hexyl-nitrate-cetane-booster/

    The more contentious thing I was told to do is chuck in 300ml of low-ash 2-stroke mineral oil. I first did it on an old smokey Mazda MPV when I bought it used 10-years ago. I did eventually get rid of the smokiness but I cannot be sure it was anything I chucked in to the tank or just because I drove it long distances on autobahns.

    I've done the same on every diesel I've bought since (never a new one) on every third fill-up for the first 10 or so. Now I just fill up with the expensive stuff in winter, probably every 3-fills. Nothing technical or scientific about it, just an unexplanable feeling that I am doing something good for the engine. I also drive a 320D.
     
    • Agree Agree x 1
  10. RevPaul

    RevPaul Senior Member

    Apr 21, 2020
    886
    243
    Cheshire, UK
    I've had three oil burners, A 54 plate Renault Grand Scenic 1.9 dCi, a 08 plate VW Touran 2.0 TDi Sport, and currently a VW Touran 2.0 TDi SLE.

    SWMBO and I and our 2 daughters have been camping and touring all over France every year since 2007 and dipping into Belgium, Germany, Spain and Switzerland on those trips. The VWs have also been "ambulances" (for our aging parents) and removal vans nationally for our daughters.

    The Renault was the worst car I've ever owned; bought from new and was a complete disaster 56,000 miles in 5.5 years (2 turbos, 1 clutch, 2 sets of discs front and rear, and spent 9 months of my last year of ownership in the garage) ran on regular diesel only, but with a history like that it doesn't really prove anything.

    The 08 Touran bought in 2011 with 21,000 miles on the clock and traded in 13yrs later for the current Touran with 186,000 miles on the clock (Original clutch, original exhaust, one replacement waste gate (under warranty) after ~3 years).

    The waste gate was clogged with carbon and not closing properly, so I moved to Shell V-Power and have stayed with that and premium diesel ever since. I can feel an improvement in performance and noticed an improvement mileage; the 08 Touran consistently averaging 49mpg over its life(I felt like I'd shot the dog when I traded it in last year).

    Is premium economical? For me I'd say yes, iff the premium is ~9pence per litre: Over that (as some Shell garages are wont to do) and I'd say probably not, but the life I got out of the first Touran would suggest that the chemicals do keep the engine in tip top condition.

    The "new" Touran is currently averaging ~52mpg so I don't see me changing to regular.

    The bike is only run on E5 premium petrol (usually Shell V-Power) for the reasons expressed in this and other threads.
     
    • Agree Agree x 3
  11. Baza

    Baza Elite Member

    Jul 25, 2020
    4,376
    750
    Amazing Grace
    Yes, on my previous BM, a 420d Grand Coupé I could get over 60 mpg on a run. I tend to stick with Shell or BP after a tank fill at Tescos left us with producing the most obnoxious smell imaginable. It took a number of refills to get rid of the smell. My current X3 30d is giving 40.2 average at the moment which, again, I’m amazed at.

    With regard to using premium gas in the bikes, I again tend to stick with Shell or BP and probably do it 50% of the time. I need to check out Esso premium gas as I believe it is ethanol free.
     
    • Like Like x 1
    • Agree Agree x 1
  12. Baza

    Baza Elite Member

    Jul 25, 2020
    4,376
    750
    Amazing Grace
    Yes, on my previous BM, a 420d Grand Coupé I could get over 60 mpg on a run. I tend to stick with Shell or BP after a tank fill at Tescos left us with producing the most obnoxious smell imaginable. It took a number of refills to get rid of the smell. My current X3 30d is giving 40.2 average at the moment which, again, I’m amazed at.

    With regard to using premium gas in the bikes, I again tend to stick with Shell or BP and probably do it 50% of the time. I need to check out Esso premium gas as I believe it is ethanol free.
     
    • Agree Agree x 1
Loading...

Share This Page