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They calculated it differently, the cheapest was probably 92 RON. And their 93 is our 97 or similar. But the point taken the petrol out there is not great!

 

This guy explains really well what Octane rating is: http://www.youtube.com/watch?v=cfhTTuxF6Mk

US and Europe calculate it in different ways which makes US fuel look like it has a lower rating but in reality they've got the same rating. US shows the average of the Research Octane Number (RON) and Motor Octane Number (MON) rating, which is the Anti-Knock Index (AKI) while Europe just shows the RON rating which gives a higher number than the MON rating.

More info from wiki: The most common type of octane rating worldwide is the Research Octane Number (RON). RON is determined by running the fuel in a test engine with a variable compression ratio under controlled conditions, and comparing the results with those for mixtures of iso-octane and n-heptane (a fuel standard).

Motor Octane Number (MON), which is a better measure of how the fuel behaves when under load, as it is determined at 900 rpm engine speed, instead of the 600 rpm for RON.[1] MON testing uses a similar test engine to that used in RON testing, but with a preheated fuel mixture, higher engine speed, and variable ignition timing to further stress the fuel's knock resistance. Depending on the composition of the fuel, the MON of a modern gasoline will be about 8 to 10 points lower than the RON, however there is no direct link between RON and MON. Normally, fuel specifications require both a minimum RON and a minimum MON.

Basically MON uses a higher stress test and because of that it gives a lower Octane number as the fuel is under greater stress than when it is being tested through RON method.

tl;dr:UK and rest of Europe show the RON rating. US/Canada show the AKI rating which is the average of RON and MON rating.


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  • Managed 355 miles before I filled it up... new personal best!

  • I do 250 miles on a full tank :( And thats 95% of time taking it easy... Roll on next Sat and remap :)

  • oldschoolSTI
    oldschoolSTI

    Well I only do 5500 miles per year at most with both cars so mpg isn't really one of my concerns. I just buy a car if I like it really. At the mileage I do, life's too short imho. 

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Interesting, didn't know that. I just assumed like other things the US make, would be of inferior quality XD

So taking this a little with a pinch of salt as it was just over 8 miles.... :-)..... But beat that :-) :-) :-)

9c5402462fdfc10db9bc99ce7cd93ac2.jpg

Who needs a diesel oil burner when you have an STI :-)

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9 hours ago, dgarside said:

 

So taking this a little with a pinch of salt as it was just over 8 miles.... :-)..... But beat that :-) :-) :-)

 

9c5402462fdfc10db9bc99ce7cd93ac2.jpg

 

Who needs a diesel oil burner when you have an STI :-)

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8 miles of downhill driving? :D

Tesco Petrol Station at Prestwich via M62 to Trafford Centre at peak commute time yesterday [emoji39]

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28.4 from my latest tank; generally pottering around and some spirited enjoyment. Have to say I'm well impressed that it is consistently better than my outback was [emoji2]

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Just to make you feel better sandals &dave after my magical 40mpg I managed to get about 85 miles for the last 30quids worth I put in 😂

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Just to make you feel better sandals &dave after my magical 40mpg I managed to get about 85 miles for the last 30quids worth I put in [emoji23]

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Haha pedal to the metal [emoji6][emoji592][emoji100][emoji100][emoji100]

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2 hours ago, stants said:

Just to make you feel better sandals &dave after my magical 40mpg I managed to get about 85 miles for the last 30quids worth I put in 😂

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It's all a balancing act... drive sensibly when it's busy, drive like you stole it when you feel like it... swings and roundabouts!!

Wouldn't have minded but never really got over 40mph last week that was just commuting in traffic etc

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7 hours ago, stants said:

 

Wouldn't have minded but never really got over 40mph last week that was just commuting in traffic etc

 

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Yeh I get that as well when travelling into Edinburgh for my night shifts, which is mainly why i generally get over 300 miles to a tank

I think if you really want an economical car, you need to buy a diesel -) but I hate diesels...

My MPG has improved after a replaced a Knock Sensor - there was no error code though.

Yeah, MPG discussions on WRX/STI are all very tongue in cheek for me. But I guess it's good to know and a good challenge [emoji12]

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I'm getting 50mpg!!!

 

 

 

 

 

In my wife's Yaris....... :ph34r:


Mine seems to like Tesco momentum best for mpg...both tanks when I've had to fill with that so far have returned better figures than the shell ones, with similar types of driving

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It will be interesting to see what difference i get when i get my car remapped :D

Same here, still considering getting it done before warranty expires.... Mmmmm

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  • 2 weeks later...
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I think i'm losing a few mpg's due to a busted o2 sensor...

  • 2 weeks later...

God knows what I do with my jdm wrx at 505bhp.  

But I dnt look at mpg.    I c low fuel and just fill up.  

 

Nopoint owning a performance car if watching the mpg 

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4 hours ago, Beano_wrx said:

God knows what I do with my jdm wrx at 505bhp.  

But I dnt look at mpg.    I c low fuel and just fill up.  

 

Nopoint owning a performance car if watching the mpg 

It's nice to know that you can have performance when you need it but also get decent mileage... especially if it's a daily driver!

  • 2 weeks later...
  • Author

Right, filled it up with Momentum 99 (which my car seems to like now since I changed the spark plugs!) and about to commence a week of night shifts... which means sensible motorway driving and some short town driving. This is the first full fill up since getting the remap so will be interesting to see what difference it has made!

My last tank was my best yet...33.0mpg...mostly a trip to Huddersfield and back

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8 minutes ago, david1972 said:

My last tank was my best yet...33.0mpg...mostly a trip to Huddersfield and back

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Good stuff! I'm looking forward to seeing how i get on, it was down to half a tank and I had covered 180 miles... it was mapped on this tank as well and I've been using boost a lot since the novelty hasn't worn off yet :D

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