Exactly - you can lose power going low, but rarely get it by going higher.I remember either Modern Motor or Wheels tested the 760 Turbo Volvo when it was new.
Initially they couldn't work out why the acceleration numbers were the same as the NA version. Turned out someone had fueled it up with standard petrol. Once they put premium fuel in it the Turbo version delivered the performance that it was renowned for at the time.
So if you in this case anyway, the wrong fuel meant it lost a lot of power.
Fuel Price
- Thread starter Russell Hall
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Hi.I remember either Modern Motor or Wheels tested the 760 Turbo Volvo when it was new.
Initially they couldn't work out why the acceleration numbers were the same as the NA version. Turned out someone had fueled it up with standard petrol. Once they put premium fuel in it the Turbo version delivered the performance that it was renowned for at the time.
So if you in this case anyway, the wrong fuel meant it lost a lot of power.
I completely concur with these comments, and I have posted here previously that 91, 95 & 98 petrol all has the same calorific energy content.
In the taxi drivers case, the engine was the 2.5Lt that specified 95RON. So when he filled with 91, the ECU detuned to prevent detonation or knock. That explains the increased fuel consumption. The reason I posted was that I was a bit surprised that this amounted to a 17% difference.
The aspect I considered but then discounted for the increased kms/tank was the hybrid feature, but that would tend to balance out for either 91 or 98.
Cheers.
If 91, 95, and 98 have the same calorific energy content, then why is the fuel consumption 17% higher?
I'm not asking to argue, but to learn something new for me
Hi all, let me join your forum. I don't own a French car yet, but I'm thinking of buying one. It's not a final decision yet.
Hi Pokitren welcomeIf 91, 95, and 98 have the same calorific energy content, then why is the fuel consumption 17% higher?
I'm not asking to argue, but to learn something new for me
Hi all, let me join your forum. I don't own a French car yet, but I'm thinking of buying one. It's not a final decision yet.
You do not need to have a French car just a interest in them. Then you might just get to buy one 
To give an answer to your question. All modern cars try to squeeze as much power out of the fuel as they can under all conditions. They use lots of mechanical 'tricks', electronic 'tricks', and clever design. One proven method has always been to use as high a compression ratio as possible, but this causes detonation if too high for the quality of the fuel. The fuel octane rating is a measure of this important quality needed by engines.
So the engine designer must use sensors to limit damaging detonation and the computer will retard the ignition timing and reduce turbo boost when it senses any detonation. This will happen normally sometimes but if you put lower quality fuel in then it will happen much more often and the computer will learn to keep the lower settings and will reduce the power noticeably and fuel consumption will go up. As has been pointed out in this thread.
Cheers Jaahn
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Thanks for the professional responseHi Pokitren welcome
To give an answer to your question. All modern cars try to squeeze as much power out of the fuel as they can under all conditions. They use lots of mechanical 'tricks', electronic 'tricks', and clever design. One proven method has always been to use as high a compression ratio as possible, but this causes detonation if too high for the quality of the fuel. The fuel octane rating is a measure of this important quality needed by engines.
So the engine designer must use sensors to limit damaging detonation and the computer will retard the ignition timing and reduce turbo boost when it senses any detonation. This will happen normally sometimes but if you put lower quality fuel in then it will happen much more often and the computer will learn to keep the lower settings and will reduce the power noticeably and fuel consumption will go up. As has been pointed out in this thread.
Cheers Jaahn
Meanwhile in North QLD.
i recently saw diesel at Curtin Springs $2.96 Uluru$2.70 Darwin $2.44 ,when you are outback theres not much choice, it is what it is .livestock transport guys are not happy ,trucks in the N T have 4 trailers and are over 50 metres long ,130 kph limit for cars there also .its ballistic out there at the moment ,QLD school hols and everyone going places in a hurry ,im glad im home .
Hard to justify current Australian fuel prices with Brent trading around $US 112 a barrel. It has been dearer in the past and our fuel was 80c a litre less. Analysts are still predicting price volatility in the months ahead but there is no shortage of supply, Russian oil is still flowing and at record volumes to the EU despite all the political noise. Biden and others blame the oil companies for ripping consumers. There is talk of a windfall profits tax on oil companies in the U.S. and E.U., Biden says EXXON is "making more money than God" and appeals to some sense of decency for them to lower prices. J.P Morgan/Chase has done an analysis that if sanctions had actually stopped all Russian oil exports the oil price would have risen to $US380 a barrel. They worry that the Russians may reduce supply to bring the price up. There are concerns about any spare capacity in Saudi/Opec to increase production to stabilise prices and the effect of Libya stopping exports. Interesting times. A little transparency in our fuel prices might help overcome the feeling motorists have they are being royally ripped.
Maybe buying shares in Exxon is the way to go, can't beat them so might as well join them. Should of bought in October 2020, would be making a tidy profit and could run your car, ute, truck or tractor for almost nothing.
So the new government brings a new approach and at last a Minister not afraid to point out our motorists are being ripped off by current prices. To note the discrepancy between a falling international price and pump prices. Refinery gate price $1.68 a litre for unleaded.
Australian fuel prices have no relationship with Brent crude oil, so the question of "justifying" the former vs the latter, is bunk.
Crude oil in the US, just on the other side of modest ocean, itself trades at significantly different price to Brent.
The price of crude oil is set by market forces.
The wholesale price of refined products is set by market forces, and has, at times, caused refineries to run at a loss.
The retail price of fuel is also set by market forces.
Nowhere is there any scope or need to "justify" any of those prices, as they are not set by an arbitrary decision making process requiring a justification
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Well, imagine that: a Labor minister who doesn't know how a market works, and slags off business. You could have knocked me over with a feather.
The market forces to which you ascribe the current price rises for the world-wide oil industry are certainly no "justification" at all for what is happening. A small, (so far semi-) self contained war in eastern Europe is causing the damage, but why? There appears to be little change in overall oil availability and pricing so effectively the price rises are simply price gouging by a totally un-regulated market. Similar to the same way that inflation in Australia is being boosted by greedy, excessive profit margins in all areas.
Is the US army one of those forces?
The trade in crude oil is no longer controlled by market forces but by the Biden Administration which seeks to use trade sanctions as a weapon to disadvantage chosen countries. A well established American pattern (Cuba, Iran, Venezuela). Of course the result this time is a mess, blowback, high prices and shortages for those abiding by the American sanctions regime and a reversal of normal oil trade flows. Plus an income boom for Russia. So Saudi Arabia is now an importer of discount Russian oil to meet its domestic needs so it can export more of its own oil at a premium to NATO aligned states. Indian west coast refiners are making heaps buying discount Russian oil, playing the shell trick and selling the refined product to the EU and America. Refined product is untraceable and Shell accepts all cargoes that are 51% not sanctioned oil.
Provided nobody comes up with another Clever Plan to reduce Russian oil income the price of oil will trend back to the $US85 a barrel for Brent it was at in January. If the feared recession develops it may even go down to the $65 it was at before OPEC introduced output controls. Even when the winding back of sanctions (currently taking place) extends to oil it is not clear if oil trading patterns will return to normal market driven patterns. It's very expensive sending tankers on three month voyages at $US165000 a day rather than seeking the closest supply.
Brent is the most widely used benchmark indicator of world oil prices. There is a long daily list of prices of oil grades from different countries published. Our diesel used to be refined from ESPO or Sakhalin 1 in South Korea but I have no idea what it has been replaced with. So Brent is a totally relevant indicator price for us.
Provided nobody comes up with another Clever Plan to reduce Russian oil income the price of oil will trend back to the $US85 a barrel for Brent it was at in January. If the feared recession develops it may even go down to the $65 it was at before OPEC introduced output controls. Even when the winding back of sanctions (currently taking place) extends to oil it is not clear if oil trading patterns will return to normal market driven patterns. It's very expensive sending tankers on three month voyages at $US165000 a day rather than seeking the closest supply.
Brent is the most widely used benchmark indicator of world oil prices. There is a long daily list of prices of oil grades from different countries published. Our diesel used to be refined from ESPO or Sakhalin 1 in South Korea but I have no idea what it has been replaced with. So Brent is a totally relevant indicator price for us.
An interesting aside :
With the enormous amount of crude oil being sucked out of the ground in Saudi Arabia and elsewhere, isn't there a largish amount of ground subsidence there ?
I remember reading donkeys years ago about subsidence in the US after ground water being sucked out of some large area.
With the enormous amount of crude oil being sucked out of the ground in Saudi Arabia and elsewhere, isn't there a largish amount of ground subsidence there ?
I remember reading donkeys years ago about subsidence in the US after ground water being sucked out of some large area.
They are worried about pumping more gas from a Dutch field because it causes earth tremors. Gas fracking is blamed for earth tremors in different parts of the world. I think the oil is so deep and between rock layers it's stable but who knows. There is a technique for pumping water into difficult wells to raise the oil. Saudi has big reserves, estimated 80 years. It might be the ground water is pumped from limestone which will collapse. Saudi is trying to pump 12 million barrels a day. America uses 20 million barrels a day. When an oil field closes the land is always blighted, they make an awful mess. The new oil frontier is the Arctic. To the concern of the native peoples.
The Saudis are pumping billions of litres of seawater into their voids to assist in the extraction of oil.