i usually use the petrol from normal supermarket forecourts cos its usually cheaper and the car runs fine

anyway i got a really good pay packet this month and thought id buy some stuff and better fuel

went and use the shell optimax which is amazingly expensive (about £1.25 irrc)

anyway filled the tank up and it cost about £43 but the car runs really sweet, the engine is much quieter and ive got around 100 miles more from the half tank ive used than i usually do and i havent changed how i drive, at the halfway mark on the fuel level ive done over 220miles

i know the fuel is cleaner than supermarket stuff but has anyone else noticed this?

pandasam said:

went and use the shell optimax which is amazingly expensive (about £1.25 irrc)

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So what have you used?

Shell 'V-Power'
or
BP 'Opitmax'

I've heard of the differences but not noticed it myself tbh.

I use V-power in my Stilo as it helps keep the engine clean seeings as its only using petrol for about 2% of the driving that I do, seems silly to run it on crap when its running on good stuff for the other 98% of the time

chap in the office who has a lexus was told by his garage that it was worthwhile putting in some decent stuff every 4 or 5 fill ups as the additives kept all the lines and injectors clean. Whether it's worth the extra p for the extra mpg, my commute is very regular and I know exactly what I get from a tank so maybe I'll try it next fill up and see if the extra mpg offsets the cost.

I avoid supermarket petrol like the plague. It's cheap, but as you know everything is cheap for a reason. It often lacks the detergents of higher quality and more expensive fuels.

Here's an article I wrote some 7 years ago about the then 'Optimax':
http://www.mr2.net/trackdayqueen/optimax.htm

If the ECU cannot advance the ignition timing then there cannot be any noticeable difference in the panda's performance. A good quality 95RON petrol should suffice. As discussed already, the potential gains on a turbo / super charged car with an adaptable ECU are significant. But that's not a panda!

And the claims of getting 100 miles more from half a tank are, well, just not very realistic.

I put Total Excellium 97ron in by accident a few weeks ago, and have stuck with it for a few tanks...it does appear to give better mileage although my car is fairly low miles so any improvement could be put down to some loosening off of the engine. The ambient temperature has been all over the place lately though so I can't say for certain.

Normally I'd steer clear of performance fuels because Actives/Dynamics are set up for 95 ron but this Excellium is marketed as not just for performance machines (they would say that though wouldn't they? )

According to my calculations, you only need an improvement of about 2mpg over a tankful to recoup the extra 5p it costs per litre and you are probably being a little kinder to your engine in terms of deposits on the internals...

I got stung for 1.30 a litre recently though, half asleep doh!, a markup of 10p over the 95ron...check my results on fuelly, not particularly scientific but there we go...

Dan Friel said:

And the claims of getting 100 miles more from half a tank are, well, just not very realistic.

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especially half a tiny panda tank

I wonder if the benefits of using a higher octane rated fuel might be that it retains higher level octane for longer?...I have heard the octane levels drop as the fuel has been on the forecourt a few days so you are better with the 'fresher' stuff...

95 might be 94, 93... 97 might be 96,95

then again, you do read A LOT of rubbish about fuel on internet forums and this thread can only be adding to that...

I never use supermarket petrol if I can help it, only 'Branded' fuel - mostly Shell. It is more expensive but better quality than supermarket stuff according to all the reports I've seen and I get over 40mpg in the 100HP each and every time. I did try it on V-Power a couple of times but can't say I noticed any appreciable difference but then I doubt the ECU is smart enough to adapt to the higher RON. Same was true of my MK1 MR2 but to be fair it is 20 year old.

I can believe the OP's experience moving to it from Supermarket fuel though. I went through the same epiphany with a Prelude VTEC years ago when V-Power (then Optimax) first came out and never looked back

My other car is an Accord Type R and only ever gets V-Power or, in extremis, BP Ultimate. It runs like a tractor on anything else but the ECU is set for 98 RON minimum so it's a different story to the 100HP.

Polypedates said:

My other car is an Accord Type R and only ever gets V-Power or, in extremis, BP Ultimate. It runs like a tractor on anything else but the ECU is set for 98 RON minimum so it's a different story to the 100HP.

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Same story with my JDM Integra Type-R. We only ever ran it on V-Power/BP ultimate. We never tried it on regular unleaded.

Surprising that quite a few new "normal'ish" cars still require 98 RON. Suzuki Swift Sport does, and that'll give it a few more of the stated bhp.

My 207 RC needed 97 RON. Sometimes difficult to find in the middle of the desert and was a noticeable difference when 95 had to go in. Especially to the economy - the heat / dense air won't have helped! Most local cars were calibrated to 93, same as the USA??

I might do a V-Power / Ultimate test just to convince me 100% that extra cost doesn't equate to extra miles..

I always use vpower,

robjnr said:

I always use vpower,

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Same here, i notice the difference when i don't only use Shell fuel unless i get caught out

pandasam said:

t the car runs really sweet, the engine is much quieter and ive got around 100 miles more from the half tank ive used than i usually do and i havent changed how i drive, at the halfway mark on the fuel level ive done over 220miles

i know the fuel is cleaner than supermarket stuff but has anyone else noticed this?

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dunno what it has been like in Nantwich, but we have had some hotter weather which will be helping the mpg figure a fair bit...less time to warm up and uses less in the warm air...

I always drive mine the same so I can't tell if the performance improves on different fuel, the 1.2 is so weedy over 40mph (and higher :devil that I can't honestly detect any difference...it doesn't really miss a beat whatever I feed it and is so quiet I don't hear the difference either...maybe I'm not revving it hard enough

the reasons more performance orientated vehicle require 97 octane fuel is due to is detonation resistance, especially forced in duction where the boost can remain higher without the pre det.

i know the difference in a 1.1 panda or even the 100hp would hardly be noticed but there is no harm in putting better qaulity fuel in if only to keep everything inside clean.


supermarket fuel is very good really, in england the qaulity of the fuel is generally very high, just avoid the stations where they are filling the forcourt tanks up cos all the crap at the bottom will be swirled around and then end up in your tank, use another one or just come back in half hour or so

pandasam said:

just avoid the stations where they are filling the forcourt tanks up cos all the crap at the bottom will be swirled around and then end up in your tank, use another one or just come back in half hour or so

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I think that is something of an urban myth in all honesty.

trackdayqueen said:

I think that is something of an urban myth in all honesty.

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So is the one about higher-octane fuels "cleaning out" your engine and that you should run it ever 10 tanks or so for this same reason. It's all bullcrap.

Unless your engine is tuned for high-octane fuels the only performance and mileage benefit you're getting is a lighter wallet. Some cars (like the new Mustang 5.0) can adjust engine timing etc. to run on anything from good old 92 octane swill all the way to 100 octane racing fuel, gaining some 30+hp difference between the two. This is a performance machine specifically made to make use of higher octance (not "better", just higher octane) fuels. The Panda (not even the "mighty" 100hp) is not.

Heck, 98 octane actually has a lower energy density than 92 due to the octane-raising additives, you really are best off with what the manual suggests for your car. Cleaning additives etc. etc. are all the same, they're mixed in at the refinery before delivery and the companies cross-trade with each other, that "supermarket petrol" may actually be refined by Shell or Conoco-Phillips and the stuff you buy at a Shell station may originally have been destined for a Tesco's near you. It's all the same, stop worrying about it

But as this thread clearly shows, superstitions die hard

trackdayqueen said:

I think that is something of an urban myth in all honesty.

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In the days of steel fuel tanks your tank would absolutely be sloshing around with rusty gunk.
I imagine plastic tanks these days are a lot cleaner. Has anyine here had a look inside one?

Geddes said:

In the days of steel fuel tanks your tank would absolutely be sloshing around with rusty gunk.
I imagine plastic tanks these days are a lot cleaner. Has anyine here had a look inside one?

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Yes, 45k miles on my old mk2 punto -no crap in the bottom -actually very clean.

With regard to refineries supplying fuel to other companies other than their own -this is true -but only as a basic fuel. Additives for the more expensive fuels are very unique ie V-power, Texaco High octane, etc. rember when loads of people had oxygen sensor damage a couple of years ago due to contamination of a batch of fuel -but it was only tesco and asda fuel and not shell/bp.

Regarding whether it cleans the engine internally ie decoking etc I should be able to report back in the next month -as I willl have the engine out of mine and have run it on v-power for the past 5k miles -but a 100hp engine running budget that I had apart was very badly coked.. -can post photos later..

Earlier someone mentioned that cars can run on 93 octane as used in the US -In the US the figures that are used, are not RON rating like the UK but AKI so a 93AKI is more like a 98RON as sold in the UK.

Further all modern fiats run a knock sensor and so retard the ignition to suit, (but there are limits set to the maximum advance that can be run -without a remap on standard ecu)

-Andy

shakey_hand_man said:

Regarding whether it cleans the engine internally ie decoking etc I should be able to report back in the next month -as I willl have the engine out of mine and have run it on v-power for the past 5k miles -but a 100hp engine running budget that I had apart was very badly coked.. -can post photos later..

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Without detailed information on how these cars were driven, you can't really draw any conclusions.

The coked-up engine was most likely the result of short trips where the engine only barely got up to proper running temps and possibly a driver who was afraid to rev it above 4000rpm, a textbook example of someone thinking they were being 'good' to their car when in fact they were damaging it by not letting it stretch its legs, as it were.

I see it every time I drive my parents' car, it feels 'off' until I've given it a good blast on the motorways, getting it nice and warm and getting up to the redline for a few kms. It drives like a dream for the next week or so until they bugger it up again :bang: