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Vectra 1.9 CDTi SRi 150
Renault recommend to run on 98 ron 
shouldn't be a problem.
shouldn't be a problem.
Civic Type R EK9
i use v-power feels soo much smoother
Vectra 1.9 CDTi SRi 150
Don't think mines ever had 95 ron....runs sweet Designed to run on 98 from what I see....98 badge in fuel cap.
Designed to run on 98 from what I see....98 badge in fuel cap.
Civic Type R EK9
mate spend the little extra on high octane honest
Vectra 1.9 CDTi SRi 150
Supposed to get a better MPG, should hopefully offset the extra cost of fuel.
Fletcher
ClioSport Club Member
I find my 172 idles much better on the higher octane fuels, and returns higger mpg.
Civic Type R EK9
Elise 111R
I seem to get around a rise of 4 mpg up from around 30 if i use V-power, which i always do....
I do sometimes wonder if BP would be better, but nearest station is 10 miles away in the wrong direction from where i mostly travel so havent tried any yet?
can anyone help me work out then if im getting better value for money by using v-power?
Im spending per litre around 98p as apposed 92p for normal shell and have seen an increase of 4 mpg over a whole tank?
cheers
I do sometimes wonder if BP would be better, but nearest station is 10 miles away in the wrong direction from where i mostly travel so havent tried any yet?
can anyone help me work out then if im getting better value for money by using v-power?
Im spending per litre around 98p as apposed 92p for normal shell and have seen an increase of 4 mpg over a whole tank?
cheers
MERCEDES CLS AMG
Cool blue 106 octane - run your 172 on this and it will put a smile on your face ( £35 for 20 lts so save it for the track )
C-VXR, T8 Map 220BHP
C-VXR, T8 Map 220BHP
are there any levels that become unsafe for the car. as always uses opti or ultimate but am allways a bit scared to put in "hotshot" or somthing incase it goes over the "safe" level and does more harm than good
Vectra 1.9 CDTi SRi 150
When I was at Donny they were dynoing a Porsche 966 with BP Ultimate 102. It needed a re-map before using fuel....gave peak power increase of 100bhp @ 3000rpm. I would get expert advice beore sticking something like this in....just in case
MERCEDES CLS AMG
Most modern vehicles fitted with a potentiometer / MAP sensor will detect an higher octane fuel running through the system and notify the ECU which should then advance or r****d the ignition accordingly. My clio had had an R-sport ECU fitted which did exactly that ( standard 172 will do the same )
When i ran the clio TT it was fitted with a DTA engine management system. When it was mapped it was mapped to run on 99 octane ( optimax ) if i had of put 106 octane fuel in the engine it wouldnt have made any difference as it was programmed to run on a specific fuel.
When i ran the clio TT it was fitted with a DTA engine management system. When it was mapped it was mapped to run on 99 octane ( optimax ) if i had of put 106 octane fuel in the engine it wouldnt have made any difference as it was programmed to run on a specific fuel.
LY 182
a map sensor measures manifold pressure and a potentiometer is basically a variable resisotor used in management systems in places such as throttle postition etc, they only time you are going to benifit from high octane fuel is if you actually need it, ie running high compression/ high boost on a forced induction engine as it would pink on lower octane fuel or you have ignition advanced to such a point that its pinking.
if the cars mapped to run a certain high octane the car will need it as it will pink running lower octane.
the cars not going to detect high octane fuel, and its a waste of money imo.
It's early in the morning, but I'll give it a go (no doubt I'll make a mistake)...
Clio fuel tank is about 50 litres which is 11 gallons.
If using V-Power gives an extra 4mpg, on a full tank this equals 4 x 11 = 44 extra miles.
To fill a tank of unleaded = 50 litres x 92p = £46
To fill a tank of V power = 50 litres x 98p = £49
Extra cost of a tank of V-power = £3
Hence it costs you £3 to travel the additional 44 miles the tank of V-power gives.
To compare this with unleaded you now have to work out how much it would cost you to drive 44 miles on normal unleaded.
Assuming you get the 30 mpg you claim above for normal unleaded, 44 miles requires 44/30 = 1.47 gallons
1.47 gallons x 4.54 litres per gallon = 6.67 litres
6.67 litres x 92p = £6.14
i.e. it costs you £6.14 to travel 44 miles on normal unleaded.
Hence, by using V-Power you are £3.14 and lots of smiles per tank better off.
MERCEDES CLS AMG
What a load of rubbish ??
MAP Sensor (Manifold Absolute Pressure) Measures the air pressure in the intake manifold. Changes in engine operation and speed will affect the MAP sensor reading, which the computer uses in fuel and timing calculations. Often it will have a single vacuum line connection plus an electrical connection. Some turbo charged cars also use the MAP sensor to measure barometric pressure
Mate - ive raced cars for 8 years now and know every trick in the book. There is a very big market for high octane fuel on the drag racing circuits starting from 102 - 120 octane. Have you ever tried it ?? Most people running high power turbo cars ( 300 BHP + ) run cool blue or VP - they swear by it and will not use anything else in there cars whilst racing.
http://www.motorshack.com/cgi-bin/ss000002.cgi?SECTIONID=VP_Racing_Fuels.html&NOLOGIN=1
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The ECU does NOT detect higher octane fuel and adjust to take advantage of it. It detects lower octane fuel and adjusts to prevent detonation. So there's a programmed-in maximum octane level beyond which you get no further advantage.
In racing that maximum would be set very high so you could put better fuel in and get more power. But for a road car the manufacturer is going to set that maximum fairly low so that if the knock sensor fails your engine won't be destroyed. Certainly they wouldn't set it any higher than the highest octane generally available pump fuel at the time.
Since Renault put "98 octane" on the petrol cap that's what they almost certainly set that maximum to. Below that you lose power, but the engine isn't damaged. Above that you get no further power increase from the higher octane.
It may be though that since those higher octane fuels are premium products they may blend them or put additives in that make the engine run clear and smoother. But it won't produce any more power than if it was running on 98 octane. It may feel like it though.
You can get more power with more octane by upping the compression ratio. But that's not what the ECU is changing when it detects knocking. Its only changing ignition advance. If you look at how much that changes power versus how much higher octane fuel costs you find that, yes, higher octane fuel gives more fuel economy, but not in proportion to how much extra it costs.
In racing that maximum would be set very high so you could put better fuel in and get more power. But for a road car the manufacturer is going to set that maximum fairly low so that if the knock sensor fails your engine won't be destroyed. Certainly they wouldn't set it any higher than the highest octane generally available pump fuel at the time.
Since Renault put "98 octane" on the petrol cap that's what they almost certainly set that maximum to. Below that you lose power, but the engine isn't damaged. Above that you get no further power increase from the higher octane.
It may be though that since those higher octane fuels are premium products they may blend them or put additives in that make the engine run clear and smoother. But it won't produce any more power than if it was running on 98 octane. It may feel like it though.
You can get more power with more octane by upping the compression ratio. But that's not what the ECU is changing when it detects knocking. Its only changing ignition advance. If you look at how much that changes power versus how much higher octane fuel costs you find that, yes, higher octane fuel gives more fuel economy, but not in proportion to how much extra it costs.
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C-VXR, T8 Map 220BHP
http://www.youtube.com/watch?v=smLkmCRl6n0
seems to lean to the larger the eng/ tune the more likly you get results. all moden cars etc with moden ecu's
Clio 172 mk2
Agree with you on the turbo/racing cars...If I was running a turbo car with any modifications to boost etc I'd run it on high octane fuel.
Is it really that noticable etc in a boggo 172/182 though ?
LY 182
of course theres a big market for it in drag racing, run those engines on cheap fuel and they would detonate like mad,
and to get 300 bhp out of a turbo lump its going to be running its fair share of boost, hence needing high octane to overcome the detonation.
why do you think drag cars run methanol, not because it burns any better than your average petrol but because it has so much higher octane rating therefore allowing the compression/boost needed to get the power
we are talking about clios here not drag cars, its not going to benefit from running race fuel in an engine that was designed to run standard pump fuel.
how do you propose manifold pressure is going to change so dramatically just by using a fuel with a higher octane rating?
Spot on this man!
MERCEDES CLS AMG
People ask me why i dont come on the site no more and its because of bullshit like this really - ive used the stuff for 8 years on race cars & road cars ( inc a 172 ) and it does make a difference.
Instead of copying and pasting from google websites and then coming on here thinking you know it all go and buy some and try it. This site is full of talk and no do
Later
Instead of copying and pasting from google websites and then coming on here thinking you know it all go and buy some and try it. This site is full of talk and no do
Later
saxo
i agree alot of forums talk bullshit,[well not the forum itself the people on them].
at the end of the day once the fuel air mixture enters the cylinders its still a mechanical effort that drives an engine [not inlcluding plugs]. the same principal of the very first combustion engine.
so there for if you have 95ron and 105ron the 105 is still gonna burn quicker cleaner and fuller meaning more of the air fuel mixture is gonna get burnt.
this gives less hydrocarbons.
the burning process once the fuel has ignited is nothing to do with the ecu,its a burning process from then on.all the ecu is gonna do is recieve certain signals from sensors and adjust accordingly.normally adjusting injecter open time or ignition advance.
now if your running 95ron and your cars recommended 98ron you ARE going to notice a BIG difference as the ecu has made its optimum adjustments and the fuel is a better quality and higher ron.
now if your running manufacturers spec 98ron and go to 105ron you are still gonna notice a difference as the fuel is gonna burn fuller cleaner and faster.
It didnt on mine, i didnt notice one bit of difference. Maybe if you were at the pod, it could knock off .1 of a second
Higher octane fuels,whist they dont burn slower, go through pre-flame changes slower than lower octane fuels. So overall time is a slower burn, hence more ignition advance and reduced knock sensitivity. They do not make more power because they burn faster.
saxo
so even if it doesnt run more power,its still smoother and cleaner then lower octane?
also if higher octane doesnt increase power why do dragsters use it and other forms of motorsport?
in actual fact sorry for my last post you dont actually want the fuel to burn too quick otherwise the air wont be burnt.
fuel is used to start the ignition of the air,air is what actually produces power,the fuel/air mixture enters the engine on the induction stroke[amazing that],inlet valve
the spark from the plug is the energy release which forces the piston down on the power stroke.
now a lower octane fuel will give more detonation,takes more energy to ignite [less volatile].
higher octane gives less detonation and is more volatile which means that dont need such a big energy to ignite it,
making it very advantageouse to turbo and high compression engines and also high revving engines as adding a turbo or high compression puts a bigger load on the spark to jump.
high revving engines also because they may not have time to fully recharge the ignition coil at higher rpms.
LY 182
well thats just stupid, rather than spitting your dummy and not bothering to reply prove me wrong!
just because you have run it for however long you have does not prove your point, i know for a fact the reasons behind using high octane fuel its exactly the same in 2stroke tuning aswell, the ONLY reason they are ran on methanol is so the compression can be raised.
its an old thread but i think its an interesting one.
