| hsk |
| Here in Canada we have a gas station (Mohawk and Husky) that sells 90 Octane for the same price as regular. I have read the threads about using premium fuel. Does anyone know if 90 octane would be okay ? |
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| Heat00 |
sometimes I run 89 and it's fine.
this is not really a high performance race car that requires premium.
people I know run 87 in their MDX and it runs just the same. |
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| sigp228 |
The debate will go back and forth forever I think. Here is just one of a zillion articles:
http://www.usatoday.com/money/autos...remiumgas_x.htm
Almost all the articles are the same, if it does not call for premium, it wont help. If it is recommended, then you decide if less power is worth it over the savings. If it is required, most likely you will be okay unless you floor the thing all the time or are max towing up a hill in the mountains on a hot summer day. Then I think if the manufacturer required premium and you blow up your engine, then they may a case to deny a claim. Maybe.
I found the part on this particular article interesting about the estimated HP loss of 5 percent. On our 300 hp car, that is 15hp. That is a lot of power for me to lose. Especially the price difference. My wife fills up the X one a week, average 18 gallons per fill up. That is 3.60 cents per fill up extra so in a year it only costs me an extra 187.20. Close to the articles 171 in his example. I did buy a 40k vehicle to worry about 180 bucks a year. I want my extra 15hp. |
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| jim.mdx |
quote:
Originally posted by hsk
Here in Canada we have a gas station (Mohawk and Husky) that sells 90 Octane for the same price as regular. I have read the threads about using premium fuel. Does anyone know if 90 octane would be okay ?
I don't know about Husky, but Mohawk's premium fuel is an ethanol blend. My guess is that their mid-grade would therefore have an ethanol component.
While it may be good for the environment, I don't believe that it's good for engines or for fuel economy. Some performance vehicles recommend staying away from ethanol-blended fuels.
Just my 2c (now on par with US 2c).
jim |
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| Mike_TX |
We have a 10% ethanol blend here on virtually all gasolines (thanks, EPA :28: ), and it causes no harmful effects other than a little loss in mileage. If it's more than that at Mohawk, I'd personally shy away from it.
Otherwise, the difference between 90 octane and 91 octane isn't enough to notice.
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| csmeance |
quote:
Originally posted by Mike_TX
We have a 10% ethanol blend here on virtually all gasolines (thanks, EPA :28: ), and it causes no harmful effects other than a little loss in mileage. If it's more than that at Mohawk, I'd personally shy away from it.
Otherwise, the difference between 90 octane and 91 octane isn't enough to notice.
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agree, 90 and 91 octane won't hurt the MDX, but suing regular can as the motor is a very high compression one (to get the 300 horses out of a 6, and using regular over an extended time can cause alot of damage due to detonation. |
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| gmc74 |
There are a lot of things that go into determining which octane is right.
If you live at a high altitude (i.e. Denver) rather than 87 octane, Regular is 85, so I wouldn't worry about 90 vs 91 or 92. The octane of the fuel is all relative to the conditions that it is used in, altitude, heat, humidity, etc.
I am not sure about the X, but some cars will retard the timing to keep them from knocking. Knocking is caused when the fuel ignites too early in the cylinder, the higher the octane, the less likely this will occur in a properly maintained car. Since newer cars are "smart" they often adjust for this, which causes a loss of power. It used to be that if your car wasn't knocking, you could use regular rather than premium, but now if you do that, you car will likely fix the issue by reducing it's power.
Mike T is right on with the ethanol blend, depending on where in the country you live, the blend is part of a year, or all year. I think it is just in the more populated areas. A few years ago, we had a fuel line burst and gas was trucked in from Tucson, they said that the gas in Tucson didnt require this blend, and they had to get permission from someone (EPA?) to sell it here in Phoenix. |
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| uopercival |
I'm no expert, but I heard that cars running with 10:1 compression ratio such as the X really require higher octane levels so that you don't have knock etc.
Doesn't gas stations in Europe offer higher octane gas than what we have here? I'm pretty sure they do.
I also read on the Acura site about how they don't recommend Ehtanol blended fuel and more importantly, Honda, BMW and i believe it was GM got together and developed an additive that's 'compatible' with their engines. In north america, the only gas stations that use this particular additive is Shell and Chevron ( I think). I only remembered Shell as that's the only gas supplier in Canada to offer that additive. I remember reading about this off a link from the Acura site, but can't find it at the moment.
Anyway, you might want to look into it further. |
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| jhue |
10:1 compression ratio is really not high these days. A Honda Odyssey minivan engine has 10:1 compression ratio and is spec'd to run on regular grade gasoline. Even turbocharged engine these days have compression ratios over 10:1. It used to be that you'd rarely see forced induction street car engines with compression ratios over 8.5:1 but the BMW 335i, which is turbocharged, has > 10:1 compression ratio. The normally aspirated BMW M5 has 12:1 compression ratio.
I've never heard of a car built in the last five years that requires premium fuel but doesn't have a knock sensor so the engine can retard the spark to avoid pinging.
They specify octane ratings differently in Europe than we do here. Here it is R + M / 2, there it is just R (R=Research Octane Number, M=Motor Octane Number). |
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| gmc74 |
quote:
Originally posted by jhue
I've never heard of a car built in the last five years that requires premium fuel but doesn't have a knock sensor so the engine can retard the spark to avoid pinging.
That is what I was referring to, if this kicks in (i.e. you use lower octane fuel) you will lose power |
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