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Those of you with a std engine tune on this thread, can you honestly tell me you can detect the difference in performance or smoothness with E5 or E0 99 Ron vs E10 95 Ron?
I think it depends on your car; some cars are more sensitive than others. I could easily decipher the difference between E10 and E5 on my 118i.

After I upgraded to a 420d, we gave the 118i to my mother. My father fills up all the cars with petrol/diesel for the week, and did so for my mother also. A few weeks later she asked me why her car wasn't driving the way it did when I gave it to her - turned out my father had been filling E10 all that time and since then she's never let him fill up with E10 again. :lol2:
 

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Discussion Starter · #22 ·
As I said, I suspect a less sophisticated engine may well feel the benefit of the extra octane. I only filled up and drove home from work today, so I really haven't noticed any difference, but what with the road surfaces being what they are at this time of year, unlikely I would.
 
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Performance-wise I notice little difference between 95 & 99, but I definitely get more miles per tank out of TM99.
 

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Discussion Starter · #24 ·
Performance-wise I notice little difference between 95 & 99, but I definitely get more miles per tank out of TM99.
Hello Mr Beck!, I hope you are well, and HNY!!!! You would think, the higher the ethanol, the faster the burn, hence more miles. But how that is off-set by difference in cost of E5 and E10; who can tell. I'm sure there will be a boffin along shortly to enlighten us.
 
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I’m not a boffin but I do have a physics degree so here goes…

Economy is a good point I overlooked with my earlier skepticism. In fact Ethanol burns with less calorific value than the longer chain stuff that makes up normal petrol so it does make sense that the higher the ethanol content the lower the mpg. The 4-5p premium of M99 may well be worth it, not sure about the big extra margin Shell charge though.
 

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Those of you with a std engine tune on this thread, can you honestly tell me you can detect the difference in performance or smoothness with E5 or E0 99 Ron vs E10 95 Ron? Don't get me wrong, I prefer to fill up with TM99 when I can, which is at least every other tankful and it gives me a warm feeling to do so, but I can't say my seat of the pants dyno can tell. The car can tolerate E25 so I doubt E10 does any real harm. There is no doubt a measurable difference but I suspect it is no more than 5-10hp and when you have 335 of the buggers does it matter?

I do understand that those with engine mods actually need 99 Ron though if they have mapped for it.
You're right I can't tell the difference but I also prefer shop at Sainsburys rather than Aldi. Whilst I can afford to do so I will 😀👍
 

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I'm with everyone else in that E5/T99 gives a slight but noticeable economy bump, especially on longer journeys. Feels like it runs smoother too, but that could be in my head.

Nothing wrong with sticking this in say sainsburys 97 to boost the octane number? I only ever use Tesco momentum fuel but seems only Sainsbury's has any sort of 'premium' fuel
Can’t see it doing any harm, just give the car a quick Italian tune up after filling up as the DME needs a couple of start/stop cycles with pulls through the whole rev range to adapt to the fuel mixture. If you change it and run half the tank through without ever breaking above 4000rpm, it won't be adapted for when you next go WOT to show someone up at a set of traffic lights.
 

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I started an earlier thread on the shortage in the Coventry area. Tesco 99 is back, not sure about Shell V-Power, but still no BP Ultimate. I'll be filling up more frequently where and when the opp arises.
 

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I'm also in the NW and I've tried 3-4 different Tesco stores this past month and no 99 in any of them.

So I just used the NUL 95 they had. Car still feels rapid so cant say it's caused any issues but I'm not saving much £ either, about 5p/litre.
 

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Discussion Starter · #34 ·
Sorry guys, I did get my E numbers mixed. Momentum at Tesco this morning :celebrate:. Am so worried about my B58 knackering a piston.
 

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Tesco 99 has upped eth from 2.5 to 5%. That's shocking.
T99 has been 4-5% for years, possibly a decade or more now? Their whole thing was they use the ethanol to make up the additional octane instead of using other additives, which keeps the fuel 25p/l cheaper than branded premium.

What’s the problem with ethanol may I ask as I’m about to start running 40% ethanol with Tesco momentum
It seems from available info that cars running higher-ethanol fuel blends are more likely to experience injector failure and associated issues.

 

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T99 has been 4-5% for years, possibly a decade or more now? Their whole thing was they use the ethanol to make up the additional octane instead of using other additives, which keeps the fuel 25p/l cheaper than branded premium.



It seems from available info that cars running higher-ethanol fuel blends are more likely to experience injector failure and associated issues.

T99 was 2.5% as of around last year.
. It's now 5%.
 
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