VZ Octane Table Help
Hi Guys,
I was using BP 98 Octane for a while and found my car was really responsive.
Recently, I just used a full tank of 95 Octane from Caltex after filling up an almost empty tank.
This fuel has made my car feel more sluggish and less responsive. Iv read that the car changes between high and low octane tables. Im using 95 and the manual says 91 or higher is recommended so is it really just the fuel thats making it feel less responsive or could it be the car computer causing it to respond differently (something to do with the octane tables) cause of the lower octane?
thanks!
Right Foot Action
I've heard plenty of people say to stay away from caltex fuels! After a few months driving my VL on Vortex 95 I went to a different fuel and I swear I got better fuel economy and it felt more responsive.
EASY $30 DIY Cold Air Induction!Originally Posted by stuffedifiknow
Moderator Puppeh
Placebo? Honestly in 12 years of driving I've never ever noticed a difference using higher octane fuels. Not once.
Hand over the dog bikkies
It's not as easy as that really. A lot of people think that by putting 98 in there will be a huge difference. Some times there is sometimes there's not. If you have it tuned for 98 only then yes you will notice a difference in say a camry you will notice no different.
Welcome to the internet where people have opinions that you might not like
Alloytec Racing
i think its also placebo, expensive fuel prob causes people to drive better
Life starts at 200km/h
Hand over the dog bikkies
Err no. People get the expensive fuel, expect a big power difference and thus seek to find it. In short give it more stick because that's what the higher octane fuel does.i think its also placebo, expensive fuel prob causes people to drive better
Welcome to the internet where people have opinions that you might not like
lol Thanks guys for all the responses. I generally have always used Caltex for all my cars. I knew people were gonna say that its all in my head haha
Im not too fussed forking out a little extra if it gives me a better drive. At the moment, using the same roads etc Im gonna finish this tank which is using the 95 octane and than next week fill up with BP 98 octane and re-assess the responsiveness. I couldve sworn by the BP 98 octane fuel last week. Iv sorta developed a feel for how the car responds. for eg, when youre driving at say 60km\hr and thanplant it, the gears will revv n respond extremely well and usually always the same at the same speed. I just think it felt noticeably different on the 98 as opposed to the Caltex 95. Im gonna try it again next week or the week after. This really has me wondering.
Hope that all made sense
P-plater
I assumed everyone knew what better fuel did. You want to advance the fuel ignition timing when at high revs so that the pressure from fuel detonation is pushing in the piston shortly after top dead center.
Low octane fuel has a lower flash point, the point where a substance spontaneously combusts. You don't want this, it will cause engine damage with time. That's why we have knock sensors to detect the uncontrolled combustion. When a knock is detected the computer retards or reduces the timing advance, this results in lower power and economy. Not by much, but it will make a much bigger difference than an underdrive pulley. Of course if the computer doesnt allow for timing advance, or it doesnt have knock sensors, it will not make any difference having a higher octane fuel.
Anyone who put 91ron fuel into their 08 golf tsi would know the result of knocking in an engine.
Originally Posted by Little Red VZ Go-Kart
1. Why would you want to floor it, or move it to the red line? Especially with the lack of airbags and ABS features!? What do you hope to achieve by that??Originally Posted by HoldenV8
give everything a spray with wd40 wheels brakes that should fix the squeaks
Not really,I use 98 Ultimate because I find it really clean for the engine and helps keep it healthy, it's not all about just power, its reliability and if I have to pay $5 extra over 91 or 95 to make my car last longer then yeah it doesn't seem that expensive after all.Err no. People get the expensive fuel, expect a big power difference and thus seek to find it. In short give it more stick because that's what the higher octane fuel does.
Donating Member
Exactly. $5 extra is nothing. Buy premium and end this conversation
Hand over the dog bikkies
I know it's not all about power but a lot of people do seem to think there car is going to go a lot quicker running 98. The rest is just an added bonus.
Welcome to the internet where people have opinions that you might not like
я σ м µ и s k ι
just wondering about that 100 percent octane stuff with the ethanol that you find at united.. you think thats oright to use in a vz v6 calais? i've been using 98 ever since i got the car and usually fill up at bp or shell. i saw my mate put it in his VE calais so yeah.
Hand over the dog bikkies
Oh boy some one had to say percent. It's not a percentage.
Welcome to the internet where people have opinions that you might not like
Donating Member
Stick with the Shell and BP 98. Shell had a 100 octane fuel in 2008 called V-Racing but it didn't last very long. United are just trying to trick people to buy their fuel thinking its better. I buy Shell V-Power from the same servo from the same pump every Wednesday night.
Convert to LPG and get 110 Ron for 55c a litre
The PCM can switch between ignition tables via the information it receives from the knock sensors. The more knock it senses, the more the PCM retards engine timing.
Using 98 means less detonation than 91 at higher combustion chamber temps and therefore less knock. Less knock = more spark advance and more spark advance means a fraction more power, also fuel consumption will decrease due to an increase in efficiency.
Disclaimer: The knowledge I have comes from EFI Live in conjunction with my LS1...But surely the principles would be the same for your alloytec
я σ м µ и s k ι
F O R U M W A R R I O R
My car is tuned for BP 98. One day I was nowhere near a BP and needed fuel so chucked in some Caltex 98. Car pinged its head off under WOT. I dont know what Caltex does to their fuel but it wasnt 98ron thats for sure.
Havent used Caltex fuel since.
Silver Certified.
Turbo L98 FTW
My ecotec was tuned for vortex 98 - it loved the stuff and hated BP ultimate. My SS is tuned for BP ultimate (purely because it's easier to find) and now runs like a dog on vortex...
Maybe it's something to do with the additives they use?
F O R U M W A R R I O R
Possibly yeah.
Silver Certified.
I only use 98 octane fuels in my VS ecotec and Ive ran into bad batches on the odd occasion with caltex vortex 98, shell V power, and bp ultimate. I live up in the country and Im sure a lot of the 98 fuels start to go stale before they get used up. I mostly use the shell V power as the servos in a handly location, but I will run any of the main brand 98 octane fuels.
In the tune Im running, Ive got the timing set to advance a heap more than it normally can so it can take full advantage of the 98 octane fuels, and Ive found that I get slightly less knock counts and timing retard when running on the shell V power. We also also run 98 octane fuel in the HQ 202 ute as it was made to run on super grade petrol which was normally rated between 96-98 octane. If we put standard unleaded in it without retarding the timing,it pings like crazy, and when the timing is retarded, it runs like shit with heaps less power. I also use 98 fuels in my lawn mowers and motorbikes. When unleaded fuel was first introduced here in oz,it replaced the standard fuel and was rated at 91 octane. Standard fuels were rated between 87-89 octane. You could actually order special low compression engines from ford and holden which ran on this low octane fuel.
Turbo L98 FTW
98 octane in a lawn mower? Righto mate.
Hand over the dog bikkies
Pulsar runs better on Caltex VR ran better on BP. Go figure.
Welcome to the internet where people have opinions that you might not like
Care to tell everyone why you assume you cant use 98 octane fuels in these. Ive been doing it for years now with no problems whatsoever. The mower, whipper snipper and the chainsaw all start up way easier and run better on the higher octane fuels, also it saves pulling your guts out when first trying to start them, thats why we use it in them. Same with the kids PW50 and 80.Everything just starts and runs better on it.
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