RON95 vs RON99

[martin_a]

OK confirmed that in Germany they sell "V-Power 95" and "V-Power Racing" (100 Octane), as well as the standard FuelSave grade:

Shell Kraftstoffe - Deutschland

Not the same as "V-Power" in the UK.

Exactly - that's what i said about the expenditure on motorsport etc, they sell a brand more than anything.

Its very well to say I don't have evidence and take it to trading standards but to be honest, i don't have the time and given Flanaia's similar response [although i see you've decided not to take them to task on this...] I am not alone in the belief that V-Power is a little unstable and the RON level can change. Perhaps (unlike Optimax) it is now more likely to be 99 or never less than 99 so they can't get in trouble for that can they.

Apart from that, why do you think they do not advertise the RON rating at the pump? I'm sure most motorists simply 'buy the brand' and have no idea what the RON rating is and neither do they google it before putting the hose in their car... so why aren't Shell clear about it at the pump? What are your thoughts?

m.

 

[BTB 500]

Apart from that, why do you think they do not advertise the RON rating at the pump? I'm sure most motorists simply 'buy the brand' and have no idea what the RON rating is and neither do they google it before putting the hose in their car... so why aren't Shell clear about it at the pump? What are your thoughts?

In Germany they have two different V-Power petrol products - the 100 octane one is clearly marked on the pumps, presumably so people know which one they're getting. I suspect there would be outcry otherwise when people filled up with the wrong (more expensive) one by mistake.

In the UK there is only one V-Power petrol product, so there is no need to stick the octane rating (which would mean nothing to the majority of punters) on the pump.

This seems pretty consistent to me, like I said I very much doubt that an oil major would sell a product as 99 RON if it wasn't. It's extremely easy to test a sample and prove one way or another, and someone would have done this by now (and it would be in the papers and all over the Internet). The fact that this hasn't happened leads me to suspect it isn't true.

 

[flango]

Tesco's might well be 99ron but it doesn't have any cleaning additives & for that reason alone i'm happy to use shell

Nope that is completely wrong I can confirm 110% that Tesco 99 RON does indeed have a detergent package very similar to that of V Power & BP Ultimate and provides just as good cleaning, and if you don't believe me I hate supermarket fuels (see my other posts on subject )and would agree with you if we were talking standard fuels but Tesco premium fuel is up there with the rest of them. Also not all of Tesco fuel is supplied by Greenergy.

Taking the other comments into view if you think about it you have to have an upper and lower spec for any liquid product sold, its the same with the additive packages we sell to the oil companies, It might well be branded as 99 RON fuel but take several samples from several sites days apart and you will see the deterioration in octane rating, it's well known in the industry on any fuel not just premium but the higher the RON the faster the deterioration, so buy your fuel from a busy petol station. So the average quoted may be 99 RON but get it at a busy station accross the road from the refinery and it may be 100 RON get it at a sleepy village petrol station where it has been sitting and it may well be 98 RON. 99 RON is only guaranteed on production in the QC lab.

So how can Tesco 99 RON always be 99 RON, easy Tesco 99 RON fuel contains stabilisers (which can have a negative effect in combustion by products, exhausts and catalysts and is why other manufacturers don't use them)

 

[martin_a]

As above - that's the point I was trying to get over.

The process is Olefinic breakdown, once fuels meet air it's just what happens. As stated a bit ago, Tesco fuel seems more stable which is why a lot of club racers use it as it is consistent (which would also explain why they are happy to publish test data on it too).

Thia article has some decent chat on it but take the findings with a pinch of salt.

Thorney Motorsport - Fuel Test Results Update

m.

 

[flango]

As above - that's the point I was trying to get over.

The process is Olefinic breakdown, once fuels meet air it's just what happens. As stated a bit ago, Tesco fuel seems more stable which is why a lot of club racers use it as it is consistent (which would also explain why they are happy to publish test data on it too).

Thia article has some decent chat on it but take the findings with a pinch of salt.

Thorney Motorsport - Fuel Test Results Update

m.

^ Great article and also agrees with what we have seen over the years.

 

[prprandall51]

Bike magazine did a test with two superbikes earlier this year, a Suzuki GSX-R 1000 and a BMW S1000RR. They ran the bikes on a dyno and tried out 3-4 "super fuels" such as BP Ultimate, V-Power, etc. Between each run they flushed the tanks and lines. Both bikes have anti-knock sensors (certainly the BMW is on an individual cylinder basis). Both bikes are specified to run on 95 RON as standard.

None of the super fuels produced any increase in power at all in either bike. In their conclusion they were careful to say that the results were pertinent only to that day on those bikes with those fuel samples, however the results were fairly damning. In fact, one fuel (can't remember which one) actually reduced the max BHP developed.

 

[NISFAN]

Bike magazine did a test with two superbikes earlier this year, a Suzuki GSX-R 1000 and a BMW S1000RR. They ran the bikes on a dyno and tried out 3-4 "super fuels" such as BP Ultimate, V-Power, etc. Between each run they flushed the tanks and lines. Both bikes have anti-knock sensors (certainly the BMW is on an individual cylinder basis). Both bikes are specified to run on 95 RON as standard.

None of the super fuels produced any increase in power at all in either bike. In their conclusion they were careful to say that the results were pertinent only to that day on those bikes with those fuel samples, however the results were fairly damning. In fact, one fuel (can't remember which one) actually reduced the max BHP developed.

Quite understandable, as knock rating is a fuels ability to reduce detonation. So the additives to give higher octane ratings, in effect damp down the ability of the fuel to ignite. This also means that there is less petrol in the petrol so less energy in it too.
So if you feed high octane fuel into an engine with an ignition timing system that does not adjust for knock, or the engine is not knocking sufficiently to alter the ignition, it will produce less power, as there is less energy in the fuel. Edit to say - Marginally less power.

High octane fuel really does only benefit an engine that has a knock corrected ignition curve, or a highly tuned ignition curve that would mean it knocks on lower octane fuel. This second engine would not necessarily produce less power on the low octane fuel, but may suffer engine damaging detonation levels.

 

[prprandall51]

Quite understandable, as knock rating is a fuels ability to reduce detonation. So the additives to give higher octane ratings, in effect damp down the ability of the fuel to ignite. This also means that there is less petrol in the petrol so less energy in it too.
So if you feed high octane fuel into an engine with an ignition timing system that does not adjust for knock, or the engine is not knocking sufficiently to alter the ignition, it will produce less power, as there is less energy in the fuel.

High octane fuel really does only benefit an engine that has a knock corrected ignition curve, or a highly tuned ignition curve that would mean it knocks on lower octane fuel. This second engine would not necessarily produce less power on the low octane fuel, but may suffer engine damaging detonation levels.

So, going on what you say, and returning to the original poster's question, surely the conclusion that Bike magazine reached is generally true for modern production vehicles: there is no value in using a higher-rated fuel than specified in the owner handbook?

 

[NISFAN]

Sort of............unless the engine detects reduced levels of knock that high octane fuel gives and advances the ignition timing to suit, then there is no point filling up with high octane fuels.

In reality most modern engines do use knock sensors, and do retard/advance ignition dependant on knock levels, so there may well be a small gain in power, but interestingly this gain might be at lower than peak power revs, normally around peak torque revs, when in cylinder pressures are highest, and in engine conditions that typically produce high knock - labouring in wrong gear at low revs, for example.

Also, it is all dependant on the original ignition mapping, and the limits the ignition advance is allowed to go. Unfortunately the knock correction is normally only one way, as in retard only. This is due to the damage that could be caused to the engine if the knock sensors failed.

In reality, high octane fuel would make little or no difference to a normally aspirated engine, but can have good effects in a turbo/supercharged engine, as they have bigger detonation problems due to forced induction and inherantly high cylinder pressures.

 

[Smatt]

Well both our cars'(B200 Turbo & C230 Kompressor) manuals recommend the higher RON fuels. I have tried occasionally & not noticed an appreciable difference- certainly not enough to offset the higher cost. Hence we always use 95RON, at no apparent detriment.

 

[nick.ged]

Bike magazine did a test with two super bikes earlier this year, a Suzuki GSX-R 1000 and a BMW S1000RR. They ran the bikes on a dyno and tried out 3-4 "super fuels" such as BP Ultimate, V-Power, etc. Between each run they flushed the tanks and lines. Both bikes have anti-knock sensors (certainly the BMW is on an individual cylinder basis). Both bikes are specified to run on 95 RON as standard.

None of the super fuels produced any increase in power at all in either bike. In their conclusion they were careful to say that the results were pertinent only to that day on those bikes with those fuel samples, however the results were fairly damning. In fact, one fuel (can't remember which one) actually reduced the max BHP developed.

i have a gixer thou k7. it is designed to run on 95. from the box it makes 170 bhp. putting 98 or 99 in it when i first had it made no difference, because the ignition wasn't timed for 98 or 99.

when i fitted a yoshimura race exhaust, with std downpipes, and made no other changes, it use to pink like mad with 95, but less so with 98 or 99. ( when i mixed the two,IE 50~50 mix of 95 and 98, it DID NOT PINK, ever, in any gear at any speed.)

i have since fitted Leo Vince full race titanium hi flow exhaust, Nikko ignition module and a Dino jet kit.

the Nikko advances the timing, and the Dino jet alters the petrol requirements.

it now makes 187.5 bhp. and is so fast it shouldn't be allowed (as are most 1 liter sports motorcycles these days)

this is about 9% increase to an already high tuned engine.

i always run mixed fuel, that is to say half 95 and half 98.

i do this because i read an article about mixing fuel on benzworld, tried it and, as explained above it made a difference.

also do it in the 124. this has mega squirt, and critically, adjustable ignition, when i was tuning it i played with the timing, and could see differences between different fuel and associated timing settings.

using high octane fuel in a low output engine will make no difference.

tuning an engine to run on high octane fuel will make a world of difference.

 

[RobertoMercini]

After trying to make sense of this techno stuff which to me it is, can anyone advise whether switching to Ron 98 or 99 will make any difference in either economy or performance in my C180K Coupe?

 

[steve333]

Nope that is completely wrong I can confirm 110% that Tesco 99 RON does indeed have a detergent package very similar to that of V Power & BP Ultimate and provides just as good cleaning, and if you don't believe me I hate supermarket fuels (see my other posts on subject )and would agree with you if we were talking standard fuels but Tesco premium fuel is up there with the rest of them. Also not all of Tesco fuel is supplied by Greenergy.

Taking the other comments into view if you think about it you have to have an upper and lower spec for any liquid product sold, its the same with the additive packages we sell to the oil companies, It might well be branded as 99 RON fuel but take several samples from several sites days apart and you will see the deterioration in octane rating, it's well known in the industry on any fuel not just premium but the higher the RON the faster the deterioration, so buy your fuel from a busy petol station. So the average quoted may be 99 RON but get it at a busy station accross the road from the refinery and it may be 100 RON get it at a sleepy village petrol station where it has been sitting and it may well be 98 RON. 99 RON is only guaranteed on production in the QC lab.

So how can Tesco 99 RON always be 99 RON, easy Tesco 99 RON fuel contains stabilisers (which can have a negative effect in combustion by products, exhausts and catalysts and is why other manufacturers don't use them)

Stand corrected if tesco 99ron contains additives,i know the standard unleaded doesn't & know an old work colleague had his 6month old 7series bmw ruined by contaminated supermarket fuel a few years back

 

[nick.ged]

After trying to make sense of this techno stuff which to me it is, can anyone advise whether switching to Ron 98 or 99 will make any difference in either economy or performance in my C180K Coupe?

use what the handbook says, end of.

 

[Smatt]

After trying to make sense of this techno stuff which to me it is, can anyone advise whether switching to Ron 98 or 99 will make any difference in either economy or performance in my C180K Coupe?

economy & performance will probably both increase, but not to such an extent that it will offset the extra expense of the higher RONs!

 

[markjay]

After trying to make sense of this techno stuff which to me it is, can anyone advise whether switching to Ron 98 or 99 will make any difference in either economy or performance in my C180K Coupe?

Probably nothing you can feel... been using only super-fuels for years, either BP Ultimate 98, Texaco High-Octane 98, or Shell V-Power 99, not so much for the Octane but because of the additives and detergents - they keep your fuel system clean and your engine will love it.

 

[flango]

Stand corrected if tesco 99ron contains additives,i know the standard unleaded doesn't & know an old work colleague had his 6month old 7series bmw ruined by contaminated supermarket fuel a few years back

Yes you are right the 95 RON is sh*te and I would not go anyware near it, the Tesco fuel fiasco a couple of years back was a disaster I'm amazed anybody buys standard fuel there anymore.

When you get to the high end RON there are basically only 4 Global suppliers, so Greenergy for Tesco buy 99 RON from guess who, blend with additives & stabilisers and sell to Tesco. Incidently IIRC I think Greenergy is part owed by Tesco?

 

[markjay]

Yes you are right the 95 RON is sh*te and I would not go anyware near it, the Tesco fuel fiasco a couple of years back was a disaster I'm amazed anybody buys standard fuel there anymore.

When you get to the high end RON there are basically only 4 Global suppliers, so Greenergy for Tesco buy 99 RON from guess who, blend with additives & stabilisers and sell to Tesco. Incidently IIRC I think Greenergy is part owed by Tesco?

Just to remind everyone that when Shell Optimax was first introduced.... they had the same fiasco. iirc the initial deliveries of the new super-fuel had too much additives, and this damaged some engines (which Shell paid for).

Just to say that everyone makes mistakes - personally i am a fan of super-fuels!

 

[flango]

Just to remind everyone that when Shell Optimax was first introduced.... they had the same fiasco. iirc the initial deliveries of the new super-fuel had too much additives, and this damaged some engines (which Shell paid for).

Just to say that everyone makes mistakes - personally i am a fan of super-fuels!

Thats true optimax was a disaster on launch the GTL process and additives package was hopeless to begin with. I live by the motto never buy version 1 of anything let the early adopters make all the mistakes and learn from them, its a lot cheaper learning from other peoples mistakes.

 

[DITTRICH]

Having trawled through this thread I am interested to see people claiming that they get more mileage out of "a tank of fuel" when they buy 98 or 99 instead of 95. Whilst it undoubtedly will have some effect, the sheer number of variables affecting MPG means that it is very difficult to decide whether it is the fuel itself that is making the difference. I used to monitor fuel consumption by brimming the tank on my C230k and over the years have had the opportunity to monitor its appetite over long 6,000 mile jaunts across Europe and Western Russia.
Let us look at just some of the factors which I believe influence your MPG.

1 Driving Style acceleration (how far into the carpet does your foot go? Kickdown?)
2 Top speeds, gears, rpm (the more it spins the more fuel it uses)
3 What direction is the wind blowing in (following or against you).
4 Lights, stereo, air conditioner, heater, fan (they all use power)
5 Are your tires pumped up properly (this makes a big difference)
6 Do you travel with the windows open (increase wind resistance)
7 How much crap do you carry around in the boot (increased weight)
8 How many passengers do you carry around (more dead weight)
9 Routes which you take (flat or loads of hills)
10 Route which you take (in town - loads of start stop lights - or not)
11 The amount of traffic on the road (less traffic, less changing speed)

My experience on long trips on my own is that fuel consumption can vary by as much as +/- 10% for no apparent reason. However, the single most influential factor on THESE trips was my top speed. In Germany, I tended to use alot more fuel than in Lithuania and Latvia where the limits are very low.

So unless, you want to give up part of your life and keep a mileage log in the car I suggest that we all quite worrying about it. I did.

Les

PS the best thing I did with my 11 year old car was to chuck 2 bottles of injector cleaner into the fuel tank. The engine feels much smoother on acceleration now but maybe just me trying to justify improving things. A mechanic once recommended it to me. One thing that the more expensive fuel does prevent is causing the fuel senders in the tank to play up and tell you that your tank is empty when you know its full.