geelhoed Posted January 24, 2006 Posted January 24, 2006 Anybody using one of these fuels and noticing a difference? I usually take normal euro 95 at Tinq (cheap shell stations) but I've been hearing more and more stories of getting better mileage from the advanced fuels, which would make it worth the extra cost. Power increase seems to be a myth according to this(in german) So does anybody have inside or first hand knowledge? Quote
nre Posted January 24, 2006 Posted January 24, 2006 Just to clear things up, I think Shell v-power is the equivalent of Optimax in mainland europe... I used Optimax in my Leon Cupra and always noticed better responsiveness and better economy. Optimax generally, for whatever reason, seems to give better results on turbo/highly tuned engines. There was an article on UK tv Fifth Gear recently which found no power increase for a base spec clio but quite big increases on an Impreza, see HERE. Cheers, Neil Quote
geelhoed Posted January 24, 2006 Author Posted January 24, 2006 Ah, optimax.. Didn't know that! So not so much advantage on a 1800 zetec I suspect? Quote
JonnyBoy Posted January 24, 2006 Posted January 24, 2006 I remember Blatman saying that in order for higher octane erated fuels to be of any benefit, the engine must have a knock sensor. I tried knocking on my engine... no one came to see what I wanted, so I assumed I dont have one and have avoided Optimax. Quote
adhawkins Posted January 24, 2006 Posted January 24, 2006 Higher octane fuels can (apparently) be a benefit in a high compression engine... Andy Quote
geelhoed Posted January 24, 2006 Author Posted January 24, 2006 Yes I am aware of the technical benefits of higher octane and the knocking of the engine. I was wondering about personal experiences with these fuels in westies. Quote
langy Posted January 24, 2006 Posted January 24, 2006 I tried knocking on my engine... no one came to see what I wanted, so I assumed I dont have one and have avoided Optimax. Quote
adhawkins Posted January 24, 2006 Posted January 24, 2006 I used to use pump fuel in my Vx. Temps regularly got over 100 degrees in heavy traffic. Culminated in a blown head gasket. After fixing the head gasket, it's only ever had Optimax. Now I rarely see temps above the low 90s, even sitting in the queue at Ty Croes while Nick Algar had his 47 re-runs Andy Quote
Bean Posted January 24, 2006 Posted January 24, 2006 Running high octane means you can run more ignition advance, this can produce more power. Incidentally, I run Optimax in my cvh and it goes well. Quote
Chris_G Posted January 24, 2006 Posted January 24, 2006 There is a full 7 page test in January's EVO magazine comparing Optimax, BP ultimate, Tesco 99, Sunoco race fuel against regular 95 ron fuels and supermarket fuels. They used a Golf GTI and a BMW M5 and did rolling road tests for torque and bhp as well as driver 'feel' tests. The conclusions were mixed, the results with the Golf showed the Race fuel and BP ultimate to be the best and shell 95 to be the worst however the M5 proved to be too clever and they think the engine management may have an upper bhp figure which can be managed despite the fuel by tweaking the settings so there was much less difference between the fuels. The biggest piece of advise they seem to give is to use the busiest petrol station you can find as the freshness of the fuel was critical to the performance, more so than the specified octane rating. This meant that busy supermarket forecourts were actually getting good results due to the high turnover and resulting freshness of the fuel. Chris Quote
Chris.B Posted January 24, 2006 Posted January 24, 2006 Anybody using one of these fuels and noticing a difference? Have a look at this month's Evo. When I finally got it off my son I read the article comparing Regular, Optimax, Ultimate, Tesco Super & Race Fuel. Worth looking at. Edited to add - when I had my engine rebuilt last year, I had two maps made for my MBE ECU. The "track action" map was developed using (and assumes) Optimax or higer octane. Quote
pistonbroke Posted January 24, 2006 Posted January 24, 2006 I used to use pump fuel in my Vx. Temps regularly got over 100 degrees in heavy traffic. Culminated in a blown head gasket. After fixing the head gasket, it's only ever had Optimax. Now I rarely see temps above the low 90s, even sitting in the queue at Ty Croes while Nick Algar had his 47 re-runs Andy Yes but have you tried using only regular since the head gasket job ? If so, did it still overheat Trid optimax quite often in me zeteck , can't say I noticed any power increase but it did cure a knock at low rpm so I now do every 4th fill up with the golden liquid Quote
adhawkins Posted January 24, 2006 Posted January 24, 2006 Yes but have you tried using only regular since the head gasket job ?If so, did it still overheat No, I haven't tried it. The original owner of the car (who built the engine) almost had a fit when I told him I was using supermarket fuel... Andy Quote
Matt Williams Posted January 24, 2006 Posted January 24, 2006 In my Audi A4 18t which is supposed to use super unleaded it makes quite a bit of difference but on a Honda that I used to have it did not make any difference what to ever. Both performance and ecomony improved on the audi My conclusion is the same as others if the engine is turbo charged or requires higher than standard octaine due to modifications there can be real benefits but the mapping would need to be adjusted by a knock sensor or remap to suit desired fuel. Quote
Blatman Posted January 24, 2006 Posted January 24, 2006 A car whose "best fuel" map is for normal 95 RON unleaded will only have less power running on "Super Unleaded". More to be found here. There's lots more too... Quote
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