unleaded or permium gas?
unleaded or permium gas?
hi guys! Well, I just bought my J30 about 2 weeks ago and I'm glad to say that I'm very happy with my purchase. When I got it I was suprised to see that it takes in premium gas only. However a friend told me that I don't need to use premium gas and I would save a lot on gas money if I use unleaded. Is he right? My fear is that I would mess up something in my car down the line due to the switch in gas. However, saving money on gas these days sounds great to me. I don't put in much mileage on a day 2 day bases. Twenty mile a day or less. Any info is greatly appreciated!:)
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szh
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I would certainly strongly recommend premium gas. Particularly if you drive few miles and lower speeds. While the engine electronics will compensate to some degree for the reduced octane, some knock and pinging (even ones that you cannot "hear") is likely and these are detrimental to long-term engine reliability. While I respect the fact that gasoline costs are high for a lot of people, you would be trading short-term financial pennies for longer-term financial problem dollars.
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docsmile71
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What your friend says is true for 95% of cars out there...you get no benefit from Premium unleaded fuel. BUT...in the case of the other 5%, like the Q45, J30, and most high performance cars which run at higher compression and more aggressive timing, you should follow the manufacturers recommended fuel.
The Q and J have knock sensors so that if you use bad fuel, it will sense it and will retard the timing so that you will get less power but no detonation from the cheaper fuel.
The Q and J have knock sensors so that if you use bad fuel, it will sense it and will retard the timing so that you will get less power but no detonation from the cheaper fuel.
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elwesso
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Use only premium..... You will get better gas mileage, your car will perform better (a LOT better), and its just better......
Look at it this way.... Most places only charge 10c more for premium over regular (at least in IN), so if you fill up 20 gallons, it only saves you $2 a fill up, and say you fill up once a week, thats $8 a month, $96/yr...... pretty insignificant if you ask me, especially to keep your car healthy and happy!
The engine can only compesate for so much pinging..... what it does to do that is it retards the timing (essentially lowering the compression ratio), and that means MUCH lower performance, and lower gas mileage...... You may even get enough better gas mileage over premium/vs unleaded to offset the costs (that may be pretty drastic), or at least close......
Look at it this way.... Most places only charge 10c more for premium over regular (at least in IN), so if you fill up 20 gallons, it only saves you $2 a fill up, and say you fill up once a week, thats $8 a month, $96/yr...... pretty insignificant if you ask me, especially to keep your car healthy and happy!
The engine can only compesate for so much pinging..... what it does to do that is it retards the timing (essentially lowering the compression ratio), and that means MUCH lower performance, and lower gas mileage...... You may even get enough better gas mileage over premium/vs unleaded to offset the costs (that may be pretty drastic), or at least close......
I'm no expert. Automotive companies that sell cars designed for premium generally count using low octane gas as voiding the warranty. That alone tells me the car needs it.
All gas when mixed with air and compressed will explode stonatenously at a certain pressure and temperature depending on the octane rating. When this happens in a gasoline engine it's bad. Power is lost, the engine kicks on the outside, but inside the pistons get slapped against the walls and the bearings take a beating.
All gas when mixed with air and compressed will explode stonatenously at a certain pressure and temperature depending on the octane rating. When this happens in a gasoline engine it's bad. Power is lost, the engine kicks on the outside, but inside the pistons get slapped against the walls and the bearings take a beating.
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Q45tech
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The point is no car company in their right mind would specify premium if it wasn't necessary in the long run for engine health.
It puts them at too much of a disadvantage against those car that can run on regular all the time.
Notice lately that more and more cars require premium, the results of the horsepower wars.
It puts them at too much of a disadvantage against those car that can run on regular all the time.
Notice lately that more and more cars require premium, the results of the horsepower wars.
Re: unleaded or permium gas?
petunia wrote:However a friend told me that I don't need to use premium gas and I would save a lot on gas money if I use unleaded.
On a completely unrelated note, do you think I look best in jeans or denim?
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elwesso
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Re: unleaded or permium gas?
petunia wrote:However a friend told me that I don't need to use premium gas and I would save a lot on gas money if I use unleaded. Is he right?
With that philosophy, he obviously doesnt plan on keeping his car very long!
the J30 ECU has both high and low octane fuel and timing maps, so if the engine determines you are running a poor fuel, it goes to that set of maps. Disadvantage is that it starts on the high octane ones at every start and then changes as knocking sets in. Just not a good idea, youll get very poor performance, and even worse gas mileage, more than enough to make 10 cents extra every 20 miles quite worth it. your engine will thank you.
Your engine is the VG30DE series. A high performance, 4 valve per cylinder, varialbe valve timg, high compression engine. It requires premium fuel only. Regular only in emergency.
You will not save any money on fuel due to poorer performance alone.
Synthetic fluids highly recommended and timing belt service required at 60k for 1993 (and 1994?) Js and at 105k for 95 and up.
The thing about these cars: you gotta pay to play.
I don't even notice the price for regular anymore.
You will not save any money on fuel due to poorer performance alone.
Synthetic fluids highly recommended and timing belt service required at 60k for 1993 (and 1994?) Js and at 105k for 95 and up.
The thing about these cars: you gotta pay to play.
I don't even notice the price for regular anymore.
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Q45tech
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Oxygenated fuels contain less energy than non oxygenated......Ethanol is partially preburnt thus the O in chemical formula [C2H5OH] so you buy less BTU per gallon with ETHANOL thus you get less miles per gallon. Proven FACT.
The oxygenates are worse because they fool the O2 sensor into enrichening the mixture so that adds another 1-2% to the 3% less in fuels so the net result is 5% worse mileage on the highway at cruise........but we're only talking about 1-1.5 mpg worse with Ethanol.
Subsidize those farmers. Cut done every tree and Plant corn in every green space on Earth. Use Nuclear reactors to transform the Nitrogen in the air to fertilizer.
The only reason we have ethanol is to keep corn prices high. It actually causes more dangerous pollution than gasoline.
The oxygenates are worse because they fool the O2 sensor into enrichening the mixture so that adds another 1-2% to the 3% less in fuels so the net result is 5% worse mileage on the highway at cruise........but we're only talking about 1-1.5 mpg worse with Ethanol.
Subsidize those farmers. Cut done every tree and Plant corn in every green space on Earth. Use Nuclear reactors to transform the Nitrogen in the air to fertilizer.
The only reason we have ethanol is to keep corn prices high. It actually causes more dangerous pollution than gasoline.
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maxnix
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But the way we do it in this country consumes even more petrochemical resources for fertilizer and pesticides. It's an insane policy.Eswift wrote:at least ethanol is a renewable resource
But no one's complaining about using genetically modified corn in the alcohol, yet.__________________Brian1995 Q45 & Q45t
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Metroyed wrote:ok ok so i hear a lot of talk about using the premium gas, and i do. I think.
Anyway, here's what i know. There's Unleaded, Power Plus, and power premium at the pump. I make a compromise and grab the middle one, the Power Plus, this still ok? Or should i switch up to the premium premium stuff?
Does not matter what they call it, premium is usually 91 octane or higher and many times 93. I think it maybe lower at high altitude... like 90. I am sure Q45tech knows why this is.