So my car requires premium fuel but lately that’s become eye waveringly expensive since our inept government won’t lower fuel excise to compensate.
So I’m thinking I might put in 1/2 a tank of 98 and then half a tank of 91 or e10. Would this give me a useable blend of fuel with an octane rating somewhere between the two?
Its a jeep cherokee kl (2.4 tigershark)
There are 3 questions here but OP hasn't given enough information
So firstly does OP's car require HIGH OCTANE 98 or just PREMIUM 95?
If PREMIUM 95 is satisfactory then switch to that and save about 10c/L
There is your quick and easy answer. No need to mix.
Secondly anyone can mix fuels but the mix must comply or exceed with the vehicle's minimum octane requirements
You risk damaging your engine using a lower octane fuel so its well and truly false economy.
Thirdly if OP's car requires Premium then definitely DO NOT USE E10 !!!!!!!
Nothing wrong with mixing 98 RON with E10 of 94 RON. You will simply end up with a blended octane of 96 RON. However if your blended price is more than the price of simply buying 95 RON, then save yourself the trouble and just buy that (assuming that your car's engine does not Knock at that level; most don't).
By the way, Shell "V-Power" is merely their 95 Ron premium petrol with added etanol to bring its rating up to 98! If you want to avoid the ethanol, then buy something else such as BP.
Where can I find info V-Power have E10?
@beefmaster: G'day Beefmaster. On the V-Power pumps it says that it contains ethanol, but does not specify what percentage. I have done some additional reading online which says that any petrol can contain up to 5% ethanol without needing to disclose this. One source that I read today says that V-power normally comprises a base of 95 RON petrol, plus 5% ethanol, plus a chemical octane enhancer to raise it the rest of the way to 98 RON. However because the 95 RON base itself might have up to 5% ethanol without needing disclosure, it is possible that the final V-Power 98 might end up with up to 10% ethanol, which is why they make the disclosure on the pumps.
Thirdly if OP's car requires Premium then definitely DO NOT USE E10 !!!!!!!
Certain Eur models do support ethenol based fuels. Just that they require RON95 as minimum where as E10 in Australia is known to be RON94 unlike Europe and US&A. OP's question is more likely if they can do a mix of 98 / 91 or E10 to achieve RON95.
I used to have a car that required 95, and I exclusively filled up with E10 from United. It was always listed as 95 and was always cheaper than regular petrol. Has it changed to 94, or does it depend on the petrol station?
@jamesorion: I don't know about United (because I don't have any around), but the big chains' e10 is 94 (it says so on the pump). It's 91 mixed with 10% ethanol - which brings it up to 94RON.
Thirdly if OP's car requires Premium then definitely DO NOT USE E10 !!!!!!!
It certainly isn't a "definite". It's not uncommon for cars that take premium to take e10 too. Although certain euros want 95 octane e10, which is available here but not the standard. So you will need to look for specific branda
E10 is a blend of regular unleaded (91) petrol and ~10% ethanol hence the name.
It technically makes it 94 RON fuel but the added alcohol increases fuel consumption so many argue you're paying less for less anyway.
I went off E10 after using it in normal ICE. Especially now when it is 2c less at $2 a litre is it 1% cheaper.
Have Corolla hybrid sedan overaging 3.7L/100kms. I can't tell the difference with E10. Potentially it is because the electric motors assist the engine a lot more. The car is rated at 3.6L/100kms. I have only see lower consumption on highways 3.5L/100kms. The Camry Hybrid (OzB favourite) runs on 95 so I can't speak for that.
What year model is your Corolla Hybrid? I am thinking of buying one as a run around. Currently driving a petrol 2004 Kia Sorento which I bought for towing a caravan. At $2 a litre I'm trying to calculate how many years it would take to recoup the savings in petrol. Let's assume 15,000 km a year of driving.
@BluebirdV: 2021 so it is current model.
Corolla normal is 6L/100km and $1500 cheaper so probably work out how many ks a year you do
The problem with using E10 as a substitute for 95 is that E10 is generally only up to 10% ethanol - so the octane rating could be anywhere between 91 and 94 at some servos.
BP and Ampol don't necessarily say their E10 is 94 octane.
Shell Freedom Fuels and 7-Eleven do say theirs are 94 Octane though. I don't think they'd be liable if their E10 was actually RON91 and caused engine damage to a "min RON95" car though.
FWIW, I have considered doing a DIY blend of Caltex E-flex (RON105ish) with 91 to make a RON95/98 mix before but decided against it because E-flex was between E70 and E85 and the RON couldn't be guaranteed (and Caltex/Ampol have removed it from sale AFAIK, and it's cost prohibitive with United E85 because that doesn't follow the price cycle like E-flex did)
ol mate's comment is pretty much on the money but its a bit more complicated,
To answer the OP's question, yes you can mix two RON fuels and end up with something in the middle.
I hold an analytical chemistry degree, some of the research i was involved with blind tested the composition of unleaded fuels available in Australia, circa 2015-2016. Most people think that there is no ethanol in 91 octane fuel, this is a flat out lie. There is also a misconception that E10 is a substandard fuel.
Ethanol is used as an octane booster (meaning it increases the RON rating) and can be found in all available 91RON fuels. They don't advertise it but the lab results at the time found all suppliers, incl. all the major players (Shell,Caltex, BP, United, 7-Eleven, etc.) contained between 3% - 6% ethanol in their fuel.
E10 tested from several stations found that it contained between 6% - 12% ethanol so definitely a bit more than what was typically found in 91 but not substantially different. Across the samples this did indicate that most of the time the E10 was hovering around 94RON (above and below).
Why the range of ethanol content? All fuels are blends of different length hydrocarbons and additives, and at different levels of evaporation due to the head space in the underground tanks. Composition not only changes from brand to brand but varies at all times. Not even each petrol tanker or refinery tank is the same. Its made to be close but its never the same.
The chemistry doesn't lie, looking at ethanol content alone the numbers suggests its pretty much a marketing exercise…
While I'm no mechanical engineer and cant comment on the risks of engine knocking, id love to see some scientific empirical evidence, eg. engine knocks with this fuel but it doesn't with this one, type results. My understanding is most cars can compensate the air/fuel mix so at worst your mileage might vary a little but less than if you drive like a hoon for a week and a grandma the next.
If you want to save a buck, do the math first then if it makes sense, alternate, fill the car with 95 and run it down a half tank then top up with E10, run it all the way down then rinse repeat.
@WayWay: " no ethanol in 91 octane fuel, this is a flat out lie."
So are the engineers from Mazda who advised that E10 not be used in many Mazda/Ford cars owing to the damage it causes to the plastic components in the fuel system sadly remiss in not also advising the same for RON 91, or did those who suffered problems, leading to the testing and then closing of a Marion Rd based fuel discounter for unlawfully selling alcohol octane-boosted fuel without labelling it as such merely have over-empathic vehicles which suffered psychosomatic symptoms?
So are the engineers from Mazda who advised that E10 not be used in many Mazda/Ford cars owing to the damage it causes to the plastic components
Did those engineers not tell the marketing people?
Is E10 petrol compatible with my Mazda?
E10 Petrol is cleared for use in all Mazda vehicles fitted with petrol engines, as specified below:
All Mazda6 models from 2002 (GG/GY model) onwards
All Mazda2 models from 2003 (DY model) onwards
All Mazda3 models from 2003 (BK model) onwards
All Mazda5 models from 2004 (CR model) onwards
All MX-5 models from 2005 (NC model) onwards
All RX-8 models from 2002 (SE model) onwards
All Mazda CX-3 models
All Mazda CX-30 models
All Mazda CX-5 models
All Mazda CX-7 models
All Mazda CX-9 models
All Mazda BT-50 models from 2006 onwards
The other earlier models require petrol which contains ethanol 5% or less.
https://www.mazda.co.uk/why-mazda/news-and-events/mazda-news…
So even U91 "contained between 3% - 6% ethanol in their fuel" it will be fine according to Mazda
@terrys: There was an issue years & years ago that older cars would have components perish faster when run with E10 fuel. That limited issue blew up in the news at the time & the result is this old trope lives on to this day.
Unless you are running one of the now classic cars that had the issue & never replaced the parts that perish, E10 wont cause any particular damage because of the ethanol blend specifically.
@mitt: I could be wrong, but my understanding is that E10 has a much higher ash and sulphur content, which some cars (maybe some euros?) don't do well with in the long run.
I could be wrong, but my understanding is that E10 has a much higher ash and sulphur content
You are wrong.
When ethanol is burnt, it reacts with oxygen and produces water and carbon dioxide, that's all.
@spaceflight: It's not the ethanol per se, it's that the legal maximum sulphur content is different for different fuel types in Australia.
The legal maximum sulphur content of 91 RON fuel sold in Australia is 150ppm and for 95 RON the legal limit is 50ppm.
Some E10 unleaded petrol blends are marketed as 94 RON petrol. For example, in NSW the fuel is labelled as “Ethanol 94 (E10)”. However, as these blends use 91 RON unleaded petrol, they do not meet all fuel standards for PULP (95 RON) and can have up to 150 ppm sulphur.
Can my vehicle operate on Ethanol blend petrol?
Given that it is more expensive refine low sulphur content fuel we can expect that the sulphur content will be only slightly lower than the legal limit.
@mitt: "one of the now classic cars "
Up to 2002 - of which there are still many on the road! The damage wasn't theoretical, it happened. I doubt there has been any change in the composition of ethanol regardless of our suspension of the laws of Mathematics, so owners of those cars should maybe be warned…
@terrys: If you have a 20 years old car, it probably doesn't worth much anyway, and probably doesn't hurt risking a $2000 bomb on ethanol. Unless it's a classic costing more then you should be well-informed enough to not doing such thing on your pride.
@terrys: Solvents in anything can damage parts that aren't designed with its exposure in mind. This is the same of all solvents including ethanol. @spaceflight makes the point about Mazda it will be a similar story for Ford.
I did a quick search and couldn't find anything for unlawful sale of ethanol boosted fuel relating to Marion Rd, if you have a link then please post it. Without knowing more about it i can only assume that they dosed the fuel in a way that was outside the allowable ranges from the consumer watchdogs that monitor fuel at stations around the country. Ethanol being both cheap and readily available was probably the dosing chemical of choice.
Solvents in anything can damage parts that aren't designed with its exposure in mind. This is the same of all solvents including ethanol
Let's not forget that petrol is a solvent too.
@terrys: Pretty sure when I went to high school & did chemistry project on pros & cons of ethanol as a fuel ->
ethanol was in 91RON fuel already in Australia & pretty easily confirmed in allocated high school textbook on the topic. This was a year or two before E10 started popping up at the servos. The concentration was just higher.
@WayWay: That's really interesting.
Do you know if 95 or 98 has ethanol too? If so, it is a lower percentage?
They seem to market it as better fuel (with some other benefits depending upon the brand).
In WA it may be a little different as I think all the fuel comes from the local BP refinery (closing soon so this will change too).
@WayWay: Thank you for an interesting contribution.
Any comments on levels of water in the samples you had?
I've seen in some towns, locals' cars have had levels of fuel system corrosion (even in 'E10/ethanol fuel compatible' ones) that indicate prolonged contamination over many years.
Then again, the samples you had would have been taken from the top so not very indicative of what the occasional customer is pumping at the bowser at the end of the station's supply replenishment cycle.
@WayWay: Very good information from the perspective of chemistry.
This article discusses about fuel chemistry somewhere point#10.
https://autoexpert.com.au/posts/the-ultimate-guide-to-octane…
QUOTED:
Time to go 100 per cent propeller-head: Octane rating is an index of the knock resistance of a particular fuel compared to a laboratory standard kind of fuel called iso-octane. Which is actually 2,2,4 tri-methyl pentane - for those of you who remained awake for carbon chemistry in high school.
@WayWay: Hey science guy, not for knock on the engine but is it true some older cars/cars not specifically designed for E10 can have issues like fuel lines deteriorating and corroding or is that a myth? If it doesn't knock is it safe to use on all cars?
@juzza87: Its not a myth, older cars that relied on seals, gaskets and hose lines that are made with non-resistant plastics or rubbers are classically more susceptible to the solvent properties of ethanol and other hydrocarbon solvents normally found in fuel. Plenty of fuel lines have cracked due to age and just general use, part of this is the softening of the material used or thinning of the walls of the hose.
The age old practice of washing your hands with petrol to get grease and oils off (not really advised these days) is a testament to this.
Modern parts are commonly designed to be more resistant to the solvent effects of fuel.
Knocking is one thing, deterioration of parts another both are valid but it depends entirely on the car, the parts and the sophistication of the engine.
@WayWay: Its not just about octane though. Ethanol is lower density, so you need more of it to do the same job. Its basically like watering down the mix.
@stumo: I agree 100% i haven't mentioned energy density of the fuels, he asked if he can and is it safe.
Lets look at energy density by weight:
Petrol typically has an energy density of ~46 MJ/kg vs ethanol with an energy density of ~27MJ/kg.
(https://energyeducation.ca/encyclopedia/Energy_density#cite_…)
Looking at the difference between 91 and E10, the posts above suggest an approximate 5% ethanol difference between the two fuels,
So the real impact of the extra 5% ethanol when using the E10 you get 1.35MJ/kg vs 2.3MJ/kg in regular 91. You are giving up 0.95MJ/kg in your fuel. So as a percentage you are losing 2.1% of your fuel density.
Assuming a direct relationship between fuel range and energy density we can draw some conclusions about range.
Lets say for instance you have a car that consistently has a range of 600 km with no other variables, this means that if you changed fuel from 91 to E10 the direct impact of this change is a loss of a mere 1.26km out of your trip ( or 598.75 km).
So for a loss in range of 2.1%, does it make sense to fill up E10 or 91?
If the fuel price for E10 is $2/L as it is in much of Australia at the moment and an average 4c difference in price at the pump, that comes out at 2% of the cost to fill up.
Based on the assumptions above, if the fuel costs more than ~$2.10/ L you are probably better off buying 91, less than this price and you'll likely save money by buying E10.
Almost any mechanic warns against using E10
Not only does it increase fuel consumption, it can also cause unwanted carbon deposits in the fuel system so requiring additional servicing and maintenance costs but also could furthermore result in engine damage.
You must be joking - sorry, but that is utter crap.
I suspect you are an old guy who dealt with even older mechanics in your prime. They were suspicious of anything new as a threat to their jobs. If you listened to them you'd still be changing oil every 3000km - sorry "2000 miles" - and ripping out your EFI to put in a carby.
@derrida derider: I remembering reading, if it don't drive regularly, it's best to avoid E10 as over time the ethanol absorbs moisture from the atmosphere and you end up with water in your fuel tank. Less of a problem is you're driving regularly. Wayway could correct me
So were you after 91 but used 95?
Generally if your car is tuned for a lower octane fuel there’s no issue using a higher octane, the other way around can cause issues though.
Can you just use 95? What does the manual say and have you researched what will happen if you use a lower octane fuel?
The answer to the later is HARMFUL CARBON BUILD UP AND ENGINE DAMAGE.
No it isn't.
Higher octane fuel is harder to burn. It doesn't mean you will have carbon buildup.
And it compresses more inside the cylinder to give more power per stroke.
@Skinnerr: The fuel doesn't compress more (liquids don't compress)
Higher octane fuel will withstand higher compression (compression generates heat) before it ignites which is why I said it is harder to burn.
@Skinnerr: Your car's compression ratio is fixed. Using fuels with a lower RON can cause premature detonation (knocking) during the compression stroke. Most cars are smart enough to detect this adjust the fuel ratio's to prevent it. It might still not be great for your car though.
Arguably engine damage is possible through knocking (premature detonation) though even that is unlikely with modern adaptive electronic control of timing. Far more likely is it just loses some power and runs a bit rougher. There is no way it could cause "CARBON BUILDUP" in a car with modern EFI though - that used to be a thing with the poor mixture control of carbies.
with current day direct injection engines, carbon build up is a thing again. Typically on the valve heads.
Old timers used to mix some 91 in Diesel in winter.
For drinking to keep themselves warm?
petrol and diesel mix? doesnt mixing those types destroy the engine?
ive had a diesel car for a year now and fuel type anxiety seems to be part of ownership
What he didnt mention was the ratio. Think of it as droplets of petrol added to a bottle of diesel. A diesel engine relies on compressing air and fuel to make it go BOOM. During winter it will be colder and harder to start a diesel engine because the engine BOOM is fighting against the cold temperature. So some petrol (HIGHLY flammable) is added as a helper to make the diesel engine start easier during cold weather.
If you have a recent model diesel engine, no need to worry about the cold winters since most modern diesel engine will have the technology to warm the Air-Fuel combustion.
Glow plugs have been fitted to diesel cars for a long time.
@spaceflight: I stand corrected.
I havent worked with OLD diesel engines with glow plugs in ages. I even forgot they existed. cheers! I saw some documentary back then where truckers in the northern hemisphere in the snow would light a small fire under the engine oil sump at the start of their workday.
light a small fire under the engine oil sump at the start of their workday.
That's for a different purpose than glow plugs.
The fire is because they don't have a block heater so the oil is too thick to provide lubrication.
@mauricem: They still practice this in many parts of Russia and former soviet lands. Some people even leave the car running overnight, it's wild.
@mauricem: No you add anti geling agents to stop diesel thickening in cold weather. You don't light a fire under the tank to warm it up
@spaceflight: Yeah Im aware what winter diesel is, I regularly camp above the snow line in a diesel ute. I'm just saying I've seen people resorting to rolling a truck over a camp fire on particularly cold mornings. when maybe they haven't used enough if any anti gel or winter diesel in their trucks. You can add 5% kero instead, its not a bush remedy, BP actually recommend it!
Yes, very low ratio of petrol.
I dont think so. They are incompatible
What car - engine option?
Short term will be ok but knocking is real my friend.
KL Jeep cherokee
That takes 91?
I just looked that up as well! Seems like 91 is called "premium" in the US.
@bobbified: Americans use a different octane rating system. They use AKI, we use RON. As far as I know, all petrol engines for that Jeep should take 91.
Manual says recommended is 93 RON, but whats that in Australia?
E10 is 94 Ron. Are you sure though? It runs 87 in America, which is 91 here.
Oh dear.
Redbook states 91RON for both the 2.4 and 3.2 models
sigh What engine?
………. have you been filling up with 98 THIS WHILE TIME because you didn’t check the RON???
So my car requires premium fuel
If your car requires premium fuel and you're putting in a lower specification fuel to try and save that little bit, the amount it'll cost you to fix any problems as a result will cost you many times those "savings". I wouldn't risk it, to be honest. Stick to the minimum that's been recommended (your engine has been tuned to that).
A shandy works fine. Just gets a bit confusing for the attendant when paying.
Wouldn't you need to pay for the one type you fill first and then fill up the rest with another type? From experience, the bowser won't reset once the hose has clicked back into its place. It only resets after you have paid.
I believe it's up to the operator to authorize the pump to start.
Seems to be a thing in Perth when it's busy that people fill up and then drive away from the bowser, park and then go in and pay so the next person can start filling up instead of waiting for them to come out.
I frequently fill a 10l jerry can then the car with only one combined payment eg @ Woolworths outlet (among others).
Different fuel? I’ve filled several jerry cans and paid for them all together.
Yes, that is possible. In your scenario, you are filling the same type of fuel in your jerry can as your car, in the one go. My comment was in relation to OP's question on mixing fuels, which means there are 2 different hoses that will get used. But as @whitelie has indicated, whether consumers need to pay after hanging up one hose is dependent on every operator.
50 % of the time the next fuel type will be activated in a few seconds.
45 % I need to look over to the attendant and hold up 2 fingers.
5 % I need to go in and pay for the first fuel firstly.
It depends what the engine is designed for. If it has been designed for a certain octane rating don't go below that otherwise over the long term you will damage your engine and have a bigger problem on your hands. The problems that can occur when using the incorrect fuel are referred to as 'knocking' or 'pinging', look up those terms for more information. Or just follow the manufacturers instructions.
A modern electronically controlled engine has a knock sensor to automatically adjust the timing and mixture to the octane rating of the fuel (that computer chip is a clever little bugger). Using a lower-than-recommended RON is, within limits (I'd stick to 98 if I had a Lamborghini), unlikely to cause knocking. It will cause a significant loss of power and fuel economy though due to the suboptimal timing.
So I’m thinking I might put in 1/2 a tank of 98 and then half a tank of 91 or e10. Would this give me a useable blend of fuel with an octane rating somewhere between the two?
just buy 95 as thats the recommended minimum RON…
yes, but each time you pump E10 you risk getting a larger amount of water in the fuel. Over time, this could cost you, if left in the tank for significant periods.
Que? Water is soluble in ethanol, and therefore ethanol removes it from your tank by mixing it with the fuel. It is actually LACK of ethanol in fuel that occasionally caused water to accumulate in the past.
Yes, and even 'non-ethanol' fuel does this to a certain extent.
Excepting the water that accumulates beyond the fuel's saturation limit- consider what happens in places where tanks are not full, and undergo a large diurnal (temperature) change each day. As air moves in and out of the tank above the liquid fuel, the water vapour it contains condenses on the edges. This drips down and goes into solution in the fuel. Each day, more water vapor enters, more cools down, and more condenses into the liquid fuel below. If the fuel is not used in short order, and replenished or mixed with enough uncontaminated fuel, it will continue to absorb water until water and acids form below the fuel, causing problems over time- rusting tanks and causing fuel delivery component failure.
This happens in petrol stations as well as cars, especially when tanks are not kept topped up.
The other trouble is for places where there have been floods, a local place I found recently had flood water and mud in their tanks and were still selling fuel out of them. This must be much more common than the inspectors would realise, as the frequency of floods increases.
Yes, the old fix for water in the petrol tank was to tip in a bottle of metho (which is ethanol).
follow the manual. You will always hear different opinion with petrol. If you look after your car, follow the manual.
My car is 2 years old, it says at least 95 but I stick with 98 all the time.
My car is 2 years old, it says at least 95 but I stick with 98 all the time.
Doctor says you need to take fish oil, you eat caviar. Cool.
Salmon caviar has high amounts of DHA
My car is 2 years old, it says at least 95 but I stick with 98 all the time.
Why?
BeCaUse 98 iZ mOrE BeTTeR!
Here we ago again. As i have mentioned, tooooo mannnyyyuuu opiniooonnsssss withhhh whatttt petrooolllll yooouuuu neeeedddsds ttttooooo uuusssseeeeee.
Okay, i find 98 gives me extra kick (miles). Yes thats my experience.
Please, do not put your opinion again, because As i have mentioned, tooooo mannnyyyuuu opiniooonnsssss withhhh whatttt petrooolllll yooouuuu neeeedddsds ttttooooo uuusssseeeeee.
Trust me, don’t feel you know anything. As neither I. So lets all chill. ☺️
@Fredfloresjr: What is your measured improvement in consumption then? And is the extra cost worth it?
My experience is that premium fuel makes diddly squat difference and isn’t worth the extra $. I got more difference in consumption by not using AC
My experience is that premium fuel makes diddly squat difference and isn’t worth the extra $
That's because it doesn't make a difference when you car isn't designed to run on it.
because they want to waste money. Not up to us tightarse to judge.
The saving would be bugger all….
As an example, prices from the same servo in Perth today are $2.20, $2.12 and $1.99 for 98, 95 and 91RON.
Say you wanted 50L of fuel, so you put in 25L of both 98 and 91 which will cost you $104.75. 50L of 95 will be $106.
Going to be much bigger savings picking when you fuel up, how you drive etc.
Best answer award right here.
Maths.
Schooling noobs since 1525.
Hey, that smells like regular.. she needs premium, dude! * PREMIUM! DUUUUUDE!! *
Yes, you can mix different octane level fuels.