Correct Fuel...?

Correct Fuel...?

Author
Discussion

paulmoonraker

2,850 posts

162 months

Tuesday 2nd October 2012
quotequote all
I can just go on personal expierence. 40k in a WRX PPP on 95ron and no problems. Besides, at the risk of egging you on, it's a mappers business to talk this stuff up wink

The WRX user handbook states 95ron, which I know is at odds with the filler cap, but that's what it states. The US version of the handbook states 91ron....

BTW, it's nice to see Francis and Simon getting on. Share the love and all that...

ScoobieWRX

4,863 posts

225 months

Tuesday 2nd October 2012
quotequote all
paulmoonraker said:
I can just go on personal expierence. 40k in a WRX PPP on 95ron and no problems. Besides, at the risk of egging you on, it's a mappers business to talk this stuff up wink

The WRX user handbook states 95ron, which I know is at odds with the filler cap, but that's what it states. The US version of the handbook states 91ron....

BTW, it's nice to see Francis and Simon getting on. Share the love and all that...
You've been very lucky running a WRX on 95RON. I'll bet most of the time you drove the car with a reasonable amount mechanical sympathy in mind. You don't strike me as someone that drives 10/10ths all the time. Driving a WRX regularly hard on 95RON will have dire consequences. It has nothing to do with talking things up..it's a fact!! Hence why all these poor sods in Ireland (Eire) living out in the sticks can't get anything better than 95RON for the most part and have their cars mapped to run 95RON. They can now get 97/98RON but that's quite recent and still hard to get outside of big towns.

The USA's best pump fuel apart from E85 which is 85% Ethanol is equivalent to 98RON, but they call it 93 Octane. You're thinking of 91 Octane (95RON) not RON. They have 91RON down to 85RON in places like Colombia/South America/Africa/India etc....

I was offered a trip to Colombia two years ago to map 10 brand new WRX's for 91RON fuel. I declined for obvious reasons that had nothing to do with the language barrier as i am fluent in deigo, plus i didn't fancy doing 20yrs in a stinky Colombian gaol for aiding and abetting high speed drug smugglers.

Go to NASIOC and you see they all want to run the best possible USA fuel available which they refer to as 93 Octane, and some run a few modified scoobs on just E85 (much more common there than here), however, when you're out in the sticks as some are, hundreds of miles from decent fuel, they run 91 Octane (95RON) and have their cars mapped accordingly.

...and as for your last comment....bks!! wink


Ordinary_Chap

7,520 posts

242 months

Tuesday 2nd October 2012
quotequote all
Just to add to what you have said Francis, my '99 RB5 has stickers all over the place and wording in the manual to only use super-unleaded (97 or above).

US fuel grading is different than British/Euro fuel grading.

article said:
United States: in the US octane rating is displayed in AKI. In the Rocky Mountain (high elevation) states, 85 AKI (90 RON) is the minimum octane, and 91 AKI (95 RON) is the maximum octane available in fuel[citation needed]. The reason for this is that in higher-elevation areas, a typical naturally aspirated engine draws in less air mass per cycle because of the reduced density of the atmosphere. This directly translates to less fuel and reduced absolute compression in the cylinder, therefore deterring knock. It is safe to fill a carbureted car that normally takes 87 AKI fuel at sea level with 85 AKI fuel in the mountains, but at sea level the fuel may cause damage to the engine. A disadvantage to this strategy is that most turbocharged vehicles are unable to produce full power, even when using the "premium" 91 AKI fuel. In some east coast states, up to 94 AKI (98 RON) is available.[26] As of January, 2011, over 40 states and a total of over 2500 stations offer ethanol-based E-85 fuel with 105 AKI.[27] Often, filling stations near US racing tracks will offer higher octane levels such as 100 AKI[citation needed].
See here; http://en.wikipedia.org/wiki/Octane_rating

There's no way any Impreza turbo will run properly on UK 91' octane.

ScoobieWRX

4,863 posts

225 months

Wednesday 3rd October 2012
quotequote all
Ordinary_Chap said:
Just to add to what you have said Francis, my '99 RB5 has stickers all over the place and wording in the manual to only use super-unleaded (97 or above).

US fuel grading is different than British/Euro fuel grading.

article said:
United States: in the US octane rating is displayed in AKI. In the Rocky Mountain (high elevation) states, 85 AKI (90 RON) is the minimum octane, and 91 AKI (95 RON) is the maximum octane available in fuel[citation needed]. The reason for this is that in higher-elevation areas, a typical naturally aspirated engine draws in less air mass per cycle because of the reduced density of the atmosphere. This directly translates to less fuel and reduced absolute compression in the cylinder, therefore deterring knock. It is safe to fill a carbureted car that normally takes 87 AKI fuel at sea level with 85 AKI fuel in the mountains, but at sea level the fuel may cause damage to the engine. A disadvantage to this strategy is that most turbocharged vehicles are unable to produce full power, even when using the "premium" 91 AKI fuel. In some east coast states, up to 94 AKI (98 RON) is available.[26] As of January, 2011, over 40 states and a total of over 2500 stations offer ethanol-based E-85 fuel with 105 AKI.[27] Often, filling stations near US racing tracks will offer higher octane levels such as 100 AKI[citation needed].
See here; http://en.wikipedia.org/wiki/Octane_rating

There's no way any Impreza turbo will run properly on UK 91' octane.
97 or above as it was then. If your RB5 was being manufactured today i've no doubt the stickers would say 99RON.

95RON for our cars is ste!!

JollyGrnMonster

887 posts

196 months

Wednesday 3rd October 2012
quotequote all
paulmoonraker said:
I can just go on personal expierence. 40k in a WRX PPP on 95ron and no problems. Besides, at the risk of egging you on, it's a mappers business to talk this stuff up wink

The WRX user handbook states 95ron, which I know is at odds with the filler cap, but that's what it states. The US version of the handbook states 91ron....

BTW, it's nice to see Francis and Simon getting on. Share the love and all that...
Plugging into these cars daily and see the issues. Talk it up for what reason?
There are only 24hours in a day lol

paulmoonraker

2,850 posts

162 months

Wednesday 3rd October 2012
quotequote all
JollyGrnMonster said:
paulmoonraker said:
I can just go on personal experience. 40k in a WRX PPP on 95ron and no problems. Besides, at the risk of egging you on, it's a mappers business to talk this stuff up wink

The WRX user handbook states 95ron, which I know is at odds with the filler cap, but that's what it states. The US version of the handbook states 91ron....

BTW, it's nice to see Francis and Simon getting on. Share the love and all that...
Plugging into these cars daily and see the issues. Talk it up for what reason?
There are only 24hours in a day lol
I was only having a poke. I don't doubt that there are potential issues. However my factual statement remains about my own experience. Does anybody have their WRX handbook, if so perhaps they can have a look. I cant find a UK one on the internet (only US ones).

ScoobieWRX

4,863 posts

225 months

Wednesday 3rd October 2012
quotequote all
paulmoonraker said:
JollyGrnMonster said:
paulmoonraker said:
I can just go on personal experience. 40k in a WRX PPP on 95ron and no problems. Besides, at the risk of egging you on, it's a mappers business to talk this stuff up wink

The WRX user handbook states 95ron, which I know is at odds with the filler cap, but that's what it states. The US version of the handbook states 91ron....

BTW, it's nice to see Francis and Simon getting on. Share the love and all that...
Plugging into these cars daily and see the issues. Talk it up for what reason?
There are only 24hours in a day lol
I was only having a poke. I don't doubt that there are potential issues. However my factual statement remains about my own experience. Does anybody have their WRX handbook, if so perhaps they can have a look. I cant find a UK one on the internet (only US ones).
Nobody is questioning your integrity and i don't doubt for one second you didn't have a bad experience on 95RON, but many people do and that's just with bog standard cars.

BTW....It doesn't matter what the handbook says, experience says different.

The handbook also says use 5W30 semi-synthetic for UK WRX and STi, but then i think it was 3 or 4 years ago Subaru release a statement telling owners of all Subaru across all years to stop using what the handbook specifies and run 10W40 fully synthetic instead. Go figure!! wink

VictoriaYorks

974 posts

141 months

Wednesday 3rd October 2012
quotequote all
I have the manuals in my car, I can go and have a look shortly.

VictoriaYorks

974 posts

141 months

Wednesday 3rd October 2012
quotequote all
Here's the page from my book



Edited by VictoriaYorks on Wednesday 3rd October 12:35

paulmoonraker

2,850 posts

162 months

Wednesday 3rd October 2012
quotequote all
VictoriaYorks said:
Here's the page from my book



Edited by VictoriaYorks on Wednesday 3rd October 12:35
It's hard to see on my iPhone, but it looks like a 95 to me... Worldwide they sell lots of these, and I bet probably say 20% of owners are enthusiasts like us (and hence drive miles for shell v power). God knows how Subaru cope with the number of blown engines they must receive...

VictoriaYorks

974 posts

141 months

Wednesday 3rd October 2012
quotequote all
It says 95 for WRX, 98 for STI.

The only reason I don't get Shell and go for BP is purely convenience. There is a Shell at the end of the road where I work but it's always queued into the road with taxis at 5.30 when I need to go.

I think I'm going to have to start going at lunchtime and avoid BP if that's the advice from other owners etc.

Ordinary_Chap

7,520 posts

242 months

Wednesday 3rd October 2012
quotequote all
paulmoonraker said:
VictoriaYorks said:
Here's the page from my book



Edited by VictoriaYorks on Wednesday 3rd October 12:35
It's hard to see on my iPhone, but it looks like a 95 to me... Worldwide they sell lots of these, and I bet probably say 20% of owners are enthusiasts like us (and hence drive miles for shell v power). God knows how Subaru cope with the number of blown engines they must receive...
Actually and probably completely unrelated but the number of scooby engines that go bang seems to be very high!

I wonder if my RB5 is recommended on 97 because its got the prodrive map?

Lee

ScoobieWRX

4,863 posts

225 months

Wednesday 3rd October 2012
quotequote all
VictoriaYorks said:
It says 95 for WRX, 98 for STI.

The only reason I don't get Shell and go for BP is purely convenience. There is a Shell at the end of the road where I work but it's always queued into the road with taxis at 5.30 when I need to go.

I think I'm going to have to start going at lunchtime and avoid BP if that's the advice from other owners etc.
I think Subaru are mistaken to quote the WRX on 95RON (although they do say or higher octane) because the engine differences between the WRX and STi aren't huge. AVCS, Turbo and injectors in the main and the STi has the stronger pistons so if either of those two could tolerate 95RON it would be the STi not the WRX.

The WRX gets just as internally hot as an STi and is subject to very similar cylinder pressures, ignition timing, fuelling etc... I don't really understand the logic behind their reasoning to quote the WRX as 95RON other than maybe ordinary buyers won't buy it if they feel they have to put more expensive fuel in, whereas the STi is a more driver focused/enthusiasts car and they are absolutely right to get STi drivers/enthusiasts using the highest grade fuel because they know you won't mind forking out for better fuel and will insist on it.

But in the real world there is little difference between both cars.

paulmoonraker

2,850 posts

162 months

Wednesday 3rd October 2012
quotequote all
FWIW, I don't doubt that there are not longer term issues running a WRX on 95ron. A lot of it comes down to the driver and how hard they drive the car. On balance my WRX was a motorway hack driven at 80's all the time, where as my STi was a weekend and track blaster.

However, I stand by what I say - I think its maybe not as bigger issue as has been talked up here, when set against sales volumes.

The US cars have 91ron, and as far as I know, the only difference is the ECU map (but I would be happy to be corrected).

-P

ScoobieWRX

4,863 posts

225 months

Wednesday 3rd October 2012
quotequote all
paulmoonraker said:
FWIW, I don't doubt that there are not longer term issues running a WRX on 95ron. A lot of it comes down to the driver and how hard they drive the car. On balance my WRX was a motorway hack driven at 80's all the time, where as my STi was a weekend and track blaster.

However, I stand by what I say - I think its maybe not as bigger issue as has been talked up here, when set against sales volumes.

The US cars have 91ron, and as far as I know, the only difference is the ECU map (but I would be happy to be corrected).

-P
You are getting confused with RON and Octane. It's 91 Octane which is 95RON. as for talking things up....that's been covered.



LewisScoob

30 posts

163 months

Thursday 4th October 2012
quotequote all
Here's my 2p worth... smile

The manuals may state 95 or 98 for WRX and STI repectively but a vehicle maketed in the UK must be able to run on 95 fuel.

If a car is run on 95 from day one then the ECU will have corrected timing, ignition etc to suit and start its learning process from there. Throw 98/99 in a car thats been ron on 95 all its life and it will start performing a little better and the ECU continues to learn the new setup for new fuel. Conversely, if you take a car thats been run on 98/99 all its life and run it on 95 then you run the risk of det which as Simon rightly stated, puts holes in pistons. Maybe not stright away but thats dependant on driving 'style' more than anything IMO.

Finally, to the OP. It wouldnt be running 95 and cruising that kills your car but cruising at 120 on a std top mount intercooler almost definitely will. These cars were not designed with sustained 000 speeds in mind and the limited airflow a standard scoop can draw in will not be sufficient to cool charge temps and before you know it your throwing hot air in the inlet and pop!

paulmoonraker

2,850 posts

162 months

Thursday 4th October 2012
quotequote all
ScoobieWRX said:
You are getting confused with RON and Octane. It's 91 Octane which is 95RON. as for talking things up....that's been covered.
No I am not.

http://en.wikipedia.org/wiki/Gasoline

See the octane ratings section.

ScoobieWRX

4,863 posts

225 months

Thursday 4th October 2012
quotequote all
I did and i read it properly.

It states clearly...Ordinary fuel in the UK is 91RON and premium is 95RON. How feckin old is that!! About time it was updated. scratchchin

They don't have 91RON in the UK any more, neither do they have it in the USA. They have what they term 91 Octane and 93 Octane which is 95 and 98RON respectively.

They display their grades at the pump as (R+M)/2) which is (RON+MON)/2.

e.g. UK Tesco Momentum is 99RON. Also graded as 87MON. Following the formula (99+87)/2)= 93.5 Octane. This is what it would be in the USA although they would round it off to 94 Octane.

95RON ordinary UK fuel is also 85-86MON. Following the formula you get (95+85 or 86)/2)= 90 or 90.5
They take the upper end of the MON value and round the final figure off to be 91 Octane.

Like i said you are confused with the American usage of the term Octane and what it means in RON terms.

SCEL1SE

307 posts

189 months

Thursday 4th October 2012
quotequote all
I never ran my standard wrx on 95, and never would. Although mines mapped now for V power, I always carry octane booster.
I'd also never buy a scoob that's been run on 95either. It says 98 in the filler cap for a reason, well it does on mine! And that's what I will continue to use.

RB5Bird

502 posts

194 months

Friday 5th October 2012
quotequote all
Ordinary_Chap said:
Actually and probably completely unrelated but the number of scooby engines that go bang seems to be very high!

I wonder if my RB5 is recommended on 97 because its got the prodrive map?

Lee
Yes it is, the Prodrive mapping is the reason.