Outer Limits 4x4 Board

Never paid too much attention to using premium fuels before but lately I noticed to old girl was down a bit on power and chewing a bit more fuel than normal .

Got talking to a couple of mates and i mentioned renewing the injectors and plugs etc but since im having an aftermarket computer fitted shortly I didnt want to renew it all just yet only to possibly upgrade it all later. Anyway the subject of premium fuel came up and their injector cleaning abilities etc and both mates were running it with good results.

So I ran 200lt of mobile 8000 and noticed that the low down gutlessness had mostly dissapeared and it wanted to rev a bit more freely. Economy improved marginally.

Next fill i ran 280L of shell v power and the drivability doubled and added a true 120km to a single 90L tank (550kms) possibly 600km had i driven for a while with the fuel light on. The Autronic full sequential system goes in next week so the results should be impressive but I'll post them in another topic ive already started. This will stay a fuel power topic only I hope.

I would be keen to get your feedback based on your own EXPERIENCES using different types of fuel. Searching other sites it seems certain vehicle makes respond better to a single brand of fuel ie late model fords seem to like BP ultimate as a general rule and Minis prefer Shell V Power.

Anyone else recon the extra dollars at the bowser is justified by the return.

Cheers,
Nathan

If you get the Autronic set up on premium you will realise extra power.

At the moment i suspect the premimum is improving/making up for something that may be worn or tired. Is your timing set right, maybe its out but just so happens to suit the premium fuel.

I tried 150l through my 80 and it romped through it quicker than you could drink a beer, and I took it easy. Not bothered with it since.

What are you putting the Autronic on?

Be interested in the results.

"Pour in Power" = NO.

Some cars do respond to premium well, and generally these cars are designed to run on higher octane fuels. Despite this, variances exist within the same vehicle type. Example: Dad's zook runs slightly better on 95 or 98 octane over standard unleaded; yet mine has absolutly no noticable difference between the two.

Also I know with my parents old VL Turbo Calais, that there was a difference, and that 'premium' fuel was recomended to help clean the injectors.

I think (can't be sure), that lower octane fuels attain higher combustion temperatures in identical engines, which can give better power, however the firing is more erratic and hence power is wasted. Anyway if its all to much for you, just buy a Diesel, they run on the worst quality fuels anyway.

Dont notice much difference in power in the zook but my pulsar has noticably more pickup and revs more freely on shell v power.

I have been testing both fuels from Shell. I have found no significant difference (P<0.05) between the two in economy or power. Although I got the impression that the PULP was better, I could not support the hypothesis with a statistcal test from 20 tanks of fuel. I

pour in power! avgas me up

as for premo... might resolve a few pinging issues but thats about it, overated in a sense. people seem to think there cars will go harder or its liquid horse power.. sorry lads it aint. it does help if you use a higher qaulity fuel but it can be msunderstood too..

quite a few people actually steer away from shell fuels as they are shit... BP ultimate and caltex vortex are the two top fuels. now with shell adding ethanol to there V power u get even less economy then it allready had and it smells funny to boot.

my car works its best on 7/11 premium, the dirtier it smells being pumpes in the more economy i seem to gain but ive been told by several high performance racers and just plain engine owners to stay away from shell when it needs filling

chunderlicious wrote:quite a few people actually steer away from shell fuels as they are shit... BP ultimate and caltex vortex are the two top fuels. now with shell adding ethanol to there V power u get even less economy then it allready had and it smells funny to boot.

my car works its best on 7/11 premium, the dirtier it smells being pumpes in the more economy i seem to gain but ive been told by several high performance racers and just plain engine owners to stay away from shell when it needs filling

fair but beg to differ... prove it!

ok. heres my proof

The z- is a N(0, 1) distribution, given by the equation:

\[ f(z) = \frac{1}{2 \pi} e^{\frac{-x^2}{2}} \]
The area within an interval (a,b) = normalcdf(a,b) = \[ \int_a^b e^{\frac{-z^2}{2}} \, dz \] (It is not integrable algebraically.)

The Taylor expansion of the above assists in speeding up the calculation:

\[ normalcdf(-\infty,z) = \frac{1}{2} + \frac{1}{\sqrt{2 \pi}} \sum_{k=0}^{\infty} \frac{(-1)^k x^{2k+1}}{(2k+1)2^k k!} \]

=shell sucks

BP Ulltimate is my choice. car runs so much better.
just all round better, not chugging or spitting and carrying on.
i know im not technical but it makes a difference in buick 3.8's.

chunderlicious wrote:ok. heres my proof

The z- is a N(0, 1) distribution, given by the equation:

\[ f(z) = \frac{1}{2 \pi} e^{\frac{-x^2}{2}} \]
The area within an interval (a,b) = normalcdf(a,b) = \[ \int_a^b e^{\frac{-z^2}{2}} \, dz \] (It is not integrable algebraically.)

The Taylor expansion of the above assists in speeding up the calculation:

\[ normalcdf(-\infty,z) = \frac{1}{2} + \frac{1}{\sqrt{2 \pi}} \sum_{k=0}^{\infty} \frac{(-1)^k x^{2k+1}}{(2k+1)2^k k!} \]

=shell sucks

This is a vehicle specific question, what works in yours probably won't work in mine type thing.

My current hilux I used BP ultimate or Shell Optimax when I first bought the car, I really cant tell the difference between premium and standard ULP in this vehicle. Due to the cost I just use ULP in the hilux.

Previous vehicle, daihatsu feroza when running on ULP would overheat and generally run like shit. Lots of pinging, down on power. Would particularly notice it if filling up at generic servos like matilda ect. Coming back from Fraser on the highway I just spat the dummy and filled it up with Ultimate, wouldnt you know it, no more pinging and more power. Never looked back.

Before that my 180sx would ping violently if using anything less then BP ultimate, you wouldnt even bother using anything else. Higher the octane the bigger the bang as far as I can see, if its tuned for it there is definately potential for more power, be it by advancing the timing, leaning off the mixtures ect.

Get the autronic and have it tuned on PULP, you wont look back!

i run ultimte in the mower and my 18hp tohatsu outboard. cant find any ultimate atm due to fishing trip, but im using vortex now and it wont jump out of the water the same and is harder to start than b4.


in my patrol i run only unleaded ( oh yeah and vege oil) and seems to go god

the Paj lovesmobil diesel, but it seems to depend on which mobil servo

CHeers.

P.S just to rub it in , im having a ball

I run Premium in my Jeep Grand Cherokee V8, and while I can't say it has more power (as I don't sink the boot into it too often, except if there is a doof doof next to me which I thoroughly enjoy dragging off!!) it definitely gets better fuel economy - somewhere around 6-7 percent, and yes I have kept records of every fill in every car since I was 18 (25 years ago....)

I find Caltex Vortex 95 gives me the best results, 98 octane seems to make no difference. And I agree Shell appears to give worst results, BP runs second to Caltex.

I only need to run a couple of tanks of ULP and economy drops right off...

PULP makes a big difference with the Holden V8 in the Pootrol.... for the same amount of fuel, i worked out that i got about 20km extra out of PULP compared to ULP. Car revs better and has better acceleration as well. going up to 98 octane makes no difference.

I throw another vote in for BP Ultimate (and diesel)

In the missus old carby Vit, I could always tell from driving it when she had put BP Ultimate in it. It used to love it and pulled hard from idle. Any other fuels seemed to lose all power down low. Much better cold engine running in the morning too.

MY GU loves our local BP diesel. Not sure what the economy is around town as I don't really monitor things like that but power wise and response is always great on BP diesel.

probably because most engines are designed to run in 96RON fuel.... as is the case with any fuel sold in this country, it's swill compared to the stuff they sell overseas.

just lookin at the stats.... the alloytech is 10.2:1 compression, it would probably run a crap load better on premium.

My wifes 92 camry runs heaps more economical on premuim (aroound 90 to 100ks per tank further) Power does not seem to be a whole lot different.

I no doubt suspect that my truck is in need of a tune and it was mentioned above that the v power seems to be compensating for this but it has surprised me how much its improved it overall.

I will use another tank of shell as i currently get 10c p/l off with a promo thats running. Once i have the new computer in and dyno tuned (that way i'l know the vehicle is in a perfect state of tune i wouldnt mind giving shell, bp and mobile a comparison test and maybe do a dyno run after a couple of tanks have flushed through each brand.

This would be purely for the benefit of my vehicle only as it seems quite obvious that each vehicle respond differently.

personaly, id NEVER put PULP in my patrol, i rekon it would kill the engine...

altho when it comes to servo specific fuels, i rekon caltex is the go, followed by BP then shell. liberty has haphazard results, some of my best fuel has come from there, and also some of my worst.






i have a diesel donk btw, hence the fear of PULP

I dynotune cars and 4x4 's and due to the extra timing you can run with PULP there is always some improvement, the higher the compression the engine or the more boost, the greater the benefit of PULP. It is also a denser fuel, more energy per litre so should return better economy. I have always suggested 8000 or Ultimate to customers as Optimax has a short shelf life and looses octane fast as it ages, havent tried V power. V power is an Ethanol fuel so carries oxygen in the fuel, this leans the mixture a small amount, I have been told 0.01 Lambda but havent tried to test it myself.
For example on 91 my XR6T would ping on 6psi, I can run it at 9psi without detonation using 8000 or Ultimate with the same total timing.
Basically higher octane allows you to tune high compression engines to peak power through correct ignition timing, low octane fuels will ping before the engine can achieve optimum timing and power.

Joel

PGS 4WD wrote:V power is an Ethanol fuel

The Shell V Power (98 RON) does not contain ethanol.

The Shell V Power Racing (100RON) however contains 5% ethanol content.

yeah i notice it in my zook .. BP ultimate
seems less sluggiesh
but it you dont notice it right away ... like 2 tanks

i also use fuel doctor ... seems to help with cold starts

but if you want just more power OUT of your fuel
go avgas
or propane ....

yeah the 1UZ doesn't ping on Premium so I could then advance the timing and set the limiter to 7500

My 30ltr Pajero needs higher octane fuel than standard(can mix 50% normal with 50% Premium) or it pings . full premium makes a very noticeable difference.
The 1ltr Zook makes no difference performance wise, but can make it had to start.
I might be wrong, but I thought BP was refined in Australia by Shell.
Only three players Shell, Caltex, and Mobil. Mobil produces/owns Ampol now.
Please correct me (with proof) if Im wrong.

BP Australia's petroleum products are manufactured by refining crude oil at the company's refineries at Kwinana in Western Australia and Bulwer Island in Queensland

taken from the BP Site

Ampol has always been assoiciated with Caltex. The Caltex brand was known as Ampol from 1949, and in 1995 they completely merged and the name Caltex was solely used.
http://www.caltex.com.au/about_his.asp

My understanding was that the BP Ultimate and Mobil 8000 came from the same refinery and the Shell was the stand alone, from my tuning that seems to be the case in their behaivior.
A number of years ago I built an AU 6 Turbo for a customer, it was tuned on Mobil 8000 and ran for 6 months without fault until the customer did a driving course at Winton where the nearest available fuel was Optimax. The car did a couple of laps before it started to break down, the customer, who was not especially mechanical, brought the car back where upon test driving I found extreme detonation. i questioned the owner about what had happened, checked the tune in the Haltech E11 vrs what I tuned it to and found no problem. We removed the plugs and found 3 of 6 earth electrodes were melted off. We drained the Optimax, refilled the tank with 8000 replaced the plugs and found everything was again OK no detonation or missfire. The engine was built with forged Arias and had survived Ok. Ever since I've avoided Optimax, I've heard from a number of tuners that the shelf life was less than 14 days, perhaps the V power is better but once bitten twice shy.
Joel

Few years ago I mixed some avgas with ULP 50/50 (my old boss had an ultralight plane ) and as a trial I ran it in my worked 202 Holden engine that had 10.5:1 compression. Could run it at 12 deg advanced and it screamed its head off. It got rid of the pinging problem and made heaps more power (good chirpys in 3rd gear) Found out that it was actually illegal to run it in a street car blew a diff and then sheared an axle but it was fun while it lasted.

Hi octane makes no diff at all to my nissan station wagon (car, not 4wd).

Of course it's not boosted so doesn't have a detonation problem running optimal timing on 91.