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Super Unleaded 98ron - wow!

Discussion in 'Engine, Drivetrain, Fuel and Exhaust' started by harrye500, Jun 22, 2018.

  1. harrye500

    harrye500 Active Member

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    Morning all, just a general ditty from me regards Super Unleaded. Last week I filled up with 98ron Super, I'd never used it before and thought I'd give it a go. I guess it was habitual filling up with std unleaded most of my driving life!

    I must say that super has given the car a HUGE boost in power, smoother and considerably quicker! What a difference that small extra 3 ron has made! Did anyone else swap from std to super and notice a big difference? No going back now, it feels like a new car again! I am also having the alloys refurbed next week (pics to follow) and brake discs and linings all round, thanks to Mercedes Grangemouth for a good price with a big discount on the parts.
     
  2. LostKiwi

    LostKiwi Senior Member

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    Never ever noticed a difference excrexon a car designed for 98 where filling with 95 negatively affects power.
    This discussion has been had many times and there is NO technical reason your car should be any better in 98 than 95 unless the car is designed for 98.
     
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  3. L John

    L John Senior Member

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    When the alloys are refurbed you will get an extra 30 hp too.
     
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  4. John Laidlaw

    John Laidlaw Senior Member

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    And a tiny boot lip spoiler will for sure give you so much downforce your face will get torn clean off in corners....:D
    Sorry- in reality if the car feels quicker it’s maybe just running a bit smoother on the 98 Ron.
    Which makes it feel quicker, maybe placebo but who cares.
     
  5. Craiglxviii

    Craiglxviii Senior Member

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    Entirely placebo effect I’m afraid. There may be a slightly improved throttle response but there won’t be any more power unless your engine is set up for 98RON in the first place, which it isn’t.
     
  6. L John

    L John Senior Member

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    He could go further. Fatter exhaust tip, graphic logos (minimum requirement is a stripe on each side), 4 point seat belt with bucket seats. External bonnet fasteners, AMG badge, all give a performance boost. Any more?

    OP, as it's such a difference in performance and a HUGE boost in power please do some repeatable tests to compare when you refill with 95.
    As said by others any performance gain is all placebo, many others have claimed an increase in performance but no one has ever had any gain in measurable tests.
    I use 98 in my bike which is designed for 95 because it is smoother but no gain in power.
    I can prove its smoother because I can ride at 30mph in top gear using 98 but have to use a lower gear at 30mph using 95 because in top gear the engine is too lumpy.
     
    Last edited: Jun 22, 2018
  7. Craiglxviii

    Craiglxviii Senior Member

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    External fuel filler anodised bright red and held down by a minimum 6 capscrews, also anodised red.
     
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  8. om613

    om613 Senior Member

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    Removing things. Like the seats and the glass.
     
  9. John Laidlaw

    John Laidlaw Senior Member

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    And the driver....
     
  10. L John

    L John Senior Member

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    AKA
     
  11. matthew k

    matthew k Senior Member

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    I agree it's placebo. In 2016 I was in the USA and driving a F30 328i hire car. Now that's a 2.0 turbo, and I could feel no difference between 87 RON and 92. There was no real difference in MPG either. I do believe there's an argument for the benefits of premium fuel (Diesel/Petrol) in relation to increased detergent content, there may be other additives that are good for the fuel delivery system. It's possible most of these benefits could be gained with only occasional use of these more expensive fuels.
     
  12. stwat

    stwat Senior Member

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    Wow. Give the guy a break.
     
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  13. John Laidlaw

    John Laidlaw Senior Member

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    I agree - I was only ribbing him lightly and as I said in my post even if it’s only placebo it really doesn’t matter, if it feels better it feels better...
     
  14. matthew k

    matthew k Senior Member

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    As they can easily add £10-12 to the cost of filling up it's good to discuss it though.
     
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  15. L John

    L John Senior Member

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    Forum banter and Matthew K has a good point too as some people do use it when 95 RON is all that is required.
    e.g. Some will put it in say one in 4 tank fulls.
     
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  16. E500 Pete

    E500 Pete Senior Member

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    On an average 50 litre fill at an extra 5p a litre it is only £2.50
     
  17. L John

    L John Senior Member

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    At the time of writing (June 2018) the average price for unleaded petrol in the UK is 129.5p and 138.1p for super unleaded.

    When I fill up with 95 RON it's usually around £70 to £75, so the extra for 98 RON would be around £5
    It's not going to break the bank but is it worth the extra 8.6p per litre on a car that doesn't need it?
     
  18. Uncle Benz

    Uncle Benz Senior Member

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    Now then, you all shout "placebo", but I don't see any science backing that up ;-)

    Higher octane fuel is more resistant to pinking, or pinging to our American friends. Any car fitted with knock sensors will retard the timing if pinking is detected to protect the pistons from potentially damaging temperatures. On a new engine designed for 95 ron you will see no advantage running 98, but once some carbon has built up and an engine runs with hotter areas in the combustion chambers than when it was new it can be a different story. If timing is regularly being retarded by the ecu from knock detection then it will run better on 98 ron, as higher octane fuel is more resistant to knocking.

    Just defending the OP, who might be feeling a bit low after mentioning it :)
     
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  19. LostKiwi

    LostKiwi Senior Member

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    To get the effect your suggesting would mean significant carbon deposits. Modern fuels/engines are also far less prone to carbon build ups than days of old. I've had heads off newer cars that have done over 100k miles and the carbon levels were so low as not to be worth doing anything about.
     
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  20. Uncle Benz

    Uncle Benz Senior Member

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    I think anyone with a Terraclean franchise would disagree with you there ;)
     

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