z22yh fuel type

patricks

Regular Member
Hi all just wondering what is the minimum grade of fuel (95ron OR 91RON) that can be used on the z22yh in europe and uk? I ask because over here in Australia the astra mk5 equipped with a z22yh puts out 110kw and 210nm compared to 114kw and 220nm in uk. Im thinking this is because here in oz this engine was detuned to accept lower grade 91ron fuel thats sold here. This being the case that means all id need to do is swap the aussie ecu for a uk one to get the proper tune??? Ideally id want the lighter mk 4 asta but finding one in decent shape is getting so hard because of its age......so im looking at newer and more plentiful mk5 astas with z22yh engine but i want it with the same power as produced in UK because mk 5 astra is a heavier car and needs the extra horses........for some reason mark 5 astra with 2.2 direct didnt get sold in uk???
 

gsi2000

Member
Europe has stricter fuel regulations than Australia, which means in Australia its fine to sell 91 ron, engine types and performance is based on being able to run on lower points fuel, putting in a premium fuel will give you very slight performance gains (try different brands to find one that suits your engine, not all premium fuels are the same) cheap fuel is false economy so worth paying that bit extra.
airbox and exhaust provides restriction so free flowing them will help also, why not remap your ecu rather than swapping to a UK version.
 

patricks

Regular Member
Europe has stricter fuel regulations than Australia, which means in Australia its fine to sell 91 ron, engine types and performance is based on being able to run on lower points fuel, putting in a premium fuel will give you very slight performance gains (try different brands to find one that suits your engine, not all premium fuels are the same) cheap fuel is false economy so worth paying that bit extra.
airbox and exhaust provides restriction so free flowing them will help also, why not remap your ecu rather than swapping to a UK version.

Cheers so if i understand u correctly the minimum grade of fuel over there is 95RON for that engine yes???? Im not actually wanting to run 91RON at all. What im trying to say is IF the engine over here has been DETUNED to accept 91 ron then that would explain why the power and torque figures are down on UK versions of the engine. Its clear to me that even if i put 95 or 98 Ron in an australian z22yh the power and torque will STILL be down on UK versions because of the base map to accept 91ron.

The z22se/z22yh family of engines is not common in Australia and i wouldnt trust anybody over here to map the ecu. Its cheaper and easier to just swap out to a UK ecu. Not sure if i would also have to swap out central locking etc too. And of course our speedos are in KMH not mph too so a few other variable i would need to consider. But a map over here costs $1000 AUD minimum and a UK ecu less than half that.
 

gsi2000

Member
There's a misconception regarding fuel grades and how they are worked out, most people are led to believe RON ratings are purely power gains and using a higher ron rating will boost power or gives you extra power, but basically the higher the ron rating the better combustion it gives in the engine, but not all cars will run better on higher ron grade, my 2.2 vectra ran much quicker on shell vpower, but wouldnt on others like bp ultimate and so on, put some STP petrol additive in too and it was quick as hell, you can run a car on a higher grade fuel but will give different results from which brand of petrol you use, my vectra diesel runs quicker and smoother on bp ultimate and my partners 1.8 vectra petrol prefers esso energy.
95RON is the minimum sold in the uk purely for regulations (why exactly it varies from country to country i have no real idea)
You are right in saying its been detuned to accept 91ron, if we used 91ron in z22se/yh the combustion would be too week and probably experience some knock or pinking, because our ecu map is allowing for a minimum grade, exactly the same in australia, if yours is tuned to run on 91, and for example you had 87ron to put in you would experience the same.

As far as what you need to change aswell as the ecu im not too sure, i would have thought ecu, transponder and chip, maybe vocky or evocarlos could help with that one. also they may be able to give you a second opinion on what i've said.
 

patricks

Regular Member
Great that confirms what i thought - 95ron is the minimum and thats the only difference so far as power and torque is concerned between oz and uk engines! That being the case an astra mk5 fitted with a z22yh in a uk spec ecu should have similar performance to an astra g with z22se despite the extra weight of the mark 5.

The transponder and chip, central locking etc should be able to be reprogrammed with opcom - but im not sure about about speedometre and trip computer - im hoping there is alternative to using UK speedos and uk mfd display units because they are in mph and mpg!!
 

gsi2000

Member
yeah ecu spec should be similar, i had a vectra c z22se. got scrapped couple of weeks ago but i'll be getting another one soon, i prefer the 2.2.
i should imagine the ecu should be programmable to your speedometer etc, if not with opcom possibly tech 2 (dealer??) there will be a way.
 
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