Reply With QuoteI havn't seen 95RON anywhere.. where do you get it from? Is there a difference in price between 95 and 98?
Well... explain the scientific method in how you measured the improvement?i found a deffinate difference between 95 and 98, y is it a waste? ive added octane booster on top of that and noticed more defference again.
Considering the ECU inthe astra/barina can't compensate for fuel higher than 95RON I am wondering how all this extra performance eventuated.
Use of increased RON fuel doesn't mean a car will produce more power. The most cost effective octanc fuel to use is the one the car was designed for. In the case of normally aspirated astras and barinas that is 95RON. Using 98RON fuel is a complete waste of money.
I reckon if we did blind tests between 95RON and 98RON fuels no one here could tell the difference.
I havn't seen 95RON anywhere.. where do you get it from? Is there a difference in price between 95 and 98?
Astra TS... 1.8 litres of fury!
Actually... I have a dyno proven 6kw (10%) gain with my 1.4L Corsa C using BP Ultimate fuel.Originally Posted by rjastra
This was dyno at a dyno day last year at GRP automotive in Brisbane... I have my dyno sheet here but no scanner
Wrong.
I'll copy and paste my description of a 'knock sensor' from a previous thread to give you an idea on how modern engines cope with higher octane fuel.
See... there is this think called a knock sensor. Your engine (upon startup) will slowly and slightly advance the timing to the highest point possible without 'pinging' which will trip off the knock sensor. This is a very random process, and there really isn't much anyone can do about playing with the setting unless you have a programable ECU (which you would find a good tune in the first place, not constantly change it). The point of 'pinging' in a car is determined alot by two main factors. One, is the octane of a fuel, and the second is the oxygen content in the air. Obviously, its hard to get optimal air conditions (ie. pure oxygen into the engine) and also hard to get consistant fuel octane (putting BP ultimate in my engine is garanteed for 98 octane... but that doesn't mean part of the batch could be 99 or 100 octane etc.). This is the reason cars tend to get 'sluggish' during hot days, as heat will disperse the oxygen in the air more, as well as increase internal heat in the engine (another factor... but a 'lesser' factor than fuel/air). On the rare occasion, your car can produce a handfull of kilowatts more thanks to higher oxygen content in the air, and good fuel in the tank.
ummm... it's what is commonly called premium unleaded.I havn't seen 95RON anywhere..
Compared to what? regular ULP or PULP? Was it done on the same day? same dyno? some dyno settings.Actually... I have a dyno proven 6kw (10%) gain with my 1.4L Corsa C using BP Ultimate fuel
In fact I think you will find the the ECU/engine is setup to work at its optimum on 95RON fuel. The ECU tries to run constantly at these settings until it encounters pinging. Then it retards timing etc until the pinging stops.I'll copy and paste my description of a 'knock sensor' from a previous thread to give you an idea on how modern engines cope with higher octane fuel.
Putting 98RON fuel in the car has no benefit as the ECU has no fueling/timing mappings for this fuel.
edit
Break. Depends on what you call agents: Agree its the purest form of fuel from the pump but even Ultimate has agents - these aid in the cleaning properties of the fuel and (in some cars) the performace gains:BP Ultime is a high octane fuel garanteed to be at least 98 octane throughout the mixture. It contains no agents, its the purest form of fuel you can get from a pump.
Quote from the BP Ultimate material saftey data sheet regarding the composition of the fuel:
2. COMPOSITION/INFORMATION ON INGREDIENTS
A complex mixture of volatile hydrocarbons containing paraffins, naphthenes, olefins and aromatics with carbon numbers predominantly between C4 and C12.
May contain oxygenates. May also contain small quantities of proprietary
performance additives.
Hazardous Components
Benzene, EINECS No. 200-753-7, CAS No. 71-43-2 F, T, R45 May cause cancer, R11 Highly flammable, R48/23/24/25 Toxic: Danger of serious damage to health by prolonged exposure through inhalation, in contact with skin and if swallowed.
Gasoline, EINECS No: 289-220-8, CAS No: 86290-81-5, T, R45 May cause cancer, R65 Harmful: may cause lung damage if swallowed, R38 Irritating to skin.
(>90%)
and a link to the doc for those who are interested:
http://www.msds.bp.com.au/pdf/ref_626_BP_Ultimate.pdf
Compared to multiple results from different people with the same car running 91 ron fuel on the same dyno (this was said to me by the dyno operature who showed me previous saved results from the same model of car previously... I did not actually see any other Corsa C's on the dyno on that day, however). My results are also 10% more than one of the other members here who put thier car on the dyno and posted thier results (they had 47kw @ wheels... I have ~54kw).
No, your missing the point. A knock sensor WILL change the mapping of a car to allow for even higher octanes of fuel. Because this is a mechanical process, gains are usually much smaller than propper tuning.... but there are still gains to be had by putting in higher octane fuel (to some degree.... as the higher the octane, the slower it burns).
This is how it works.....No, your missing the point. A knock sensor WILL change the mapping of a car to allow for even higher octanes of fuel.
In other words if the engine was designed and tested to run optimally on 95RON fuel then the base maps will be configured for the that fuel. If you run 91RON fuel it may detect pinging and retard timing etc etc to eliminate it.Based on its programming,
the PCM advances spark to a preset level for
different conditions. The preset spark advance
is typically close to the knock point because
the system relies on the knock sensor as a
warning device.
Most knock sensors send a base or “no
knocking” reference signal to the PCM.
If knocking occurs, the sensor detects the
increased vibration and increases its signal
to the PCM. The PCM then slightly retards
timing until the sensor signal returns to the
reference level.
If a temporary condition caused the knock,
the PCM will set spark timing to the
programmed advance. If the knock returns,
the PCM will cycle spark timing, advancing
timing until knock is encountered and then
retarding timing until the knock is gone.
If you run 98RON fuel in the car it will have no better performance than the 95RON fuel simply because the ECU will still run with the standard maps. It has no mystical power to determine that the fuel being used is of a higher octane and what "new" maps to use.
On modern engines with sophisticated engine management systems, the engine
can operate efficiently on fuels of a wider range of octane rating, but there
remains an optimum octane for the engine under specific driving conditions......
If you are already using the proper octane fuel, you will not obtain more
power from higher octane fuels. The engine will be already operating at
optimum settings, and a higher octane should have no effect on the management
system. Your driveability and fuel economy will remain the same. The higher
octane fuel costs more, so you are just throwing money away.
I said which is the best 98ron petrol to use, I already use BP ultimate, but wanted to know which is the best
07, BMW 335i , Graphite Metallic, Procede tune, 2.5in turboback, Hartge LSD.
Performance:
370 Rear wheel HP (276kw atw), 535nm rear wheel newton metres.
(approximately 345kw at the flywheel)
0-60mph in 4.3 seconds
Standing ¼ mile in 12.4 seconds
For more info check out:
http://www.vishnutuning.com
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