Am I the only one running 93 octane?
08-07-2004, 09:05 PM
#51
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4k miles on my new RX8.
I have an original post on terrible gas mileage. I was getting 10 city and 14 highway.
I switched from 93 to 87 octane and now, i'm getting 16/21.
No more high grade for me!
Performance is identical to high octane fuel and no other anomilies with 87.
Steve
I have an original post on terrible gas mileage. I was getting 10 city and 14 highway.
I switched from 93 to 87 octane and now, i'm getting 16/21.
No more high grade for me!
Performance is identical to high octane fuel and no other anomilies with 87.
Steve
08-07-2004, 09:54 PM
#52
Get in ma belly!!
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Hey all,
I bought my 8 new earlier this year. It now has 3k on it. I use only Shell V-Power 93 octane gas. Drove to Houston last week....all freeway. Average 20mpg.
According to Mazda USA and UK 91 or 93 octane is recommended. In fact the person I spoke to at Mazda USA personally recommended Shell V-Power!! $2.00 a gallon in the Big "D", I feel sorry for the west coast and up north 8 owners!!
I bought my 8 new earlier this year. It now has 3k on it. I use only Shell V-Power 93 octane gas. Drove to Houston last week....all freeway. Average 20mpg.
According to Mazda USA and UK 91 or 93 octane is recommended. In fact the person I spoke to at Mazda USA personally recommended Shell V-Power!! $2.00 a gallon in the Big "D", I feel sorry for the west coast and up north 8 owners!!
08-08-2004, 08:04 AM
#53
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How much more is premium from mid grade on the west coast these days? It is usuall 7-10 cents more for 93 Octane over 89 here in the Mid Atlantic. I just cant justify saving just over a dollar a fill up to get the lower grade.
I know some people believe the car runs better on 87 or 89 which they certainly have the right to do. However, if you buy a 30k sports car and fill up with 87 or 89 because of the price then you bought a too expensive car for your finances.
Dean
I know some people believe the car runs better on 87 or 89 which they certainly have the right to do. However, if you buy a 30k sports car and fill up with 87 or 89 because of the price then you bought a too expensive car for your finances.
Dean
08-08-2004, 10:06 AM
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I agree, Jason, a dollar more per tank is not going to break anyone but from what I've read here, more people are getting better milage without a loss of performance from mid-grade or regular over premium. Please correct me if I'm wrong; if I am hurting my car or if my performance is suffering, I have no problem using premium exclusively.
As a footnote, my 1990 300Z TT said "unleaded premium only", our cars say "premium recommended"; to me that's quite a difference.
As a footnote, my 1990 300Z TT said "unleaded premium only", our cars say "premium recommended"; to me that's quite a difference.
08-08-2004, 10:35 AM
#56
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Originally Posted by Joe M
As a footnote, my 1990 300Z TT said "unleaded premium only", our cars say "premium recommended"; to me that's quite a difference.
The manual actually says that 87 gas is ok. It tells you not to go below 87 octanes.
Next to the gas cap the sticker 'recommends' to use premium gas.
I think it's how Mazda wants to portray the car as something other than what it really is.
@Steve: (the green hornet guy) glad to see your mpg problem resolved.
-Peter
08-08-2004, 12:54 PM
#57
The Turkish Delight
The pinging should only come at really low AFR (air-fuel ratio) times, when the gas is so lean that pre-ignites. Since there are so many different accounts of pinging here, no pinging there, the cars must have different AFR's. This was also true in the latest RXTuner article about the Canzoomer ECU. The cars ranged in leanness/richness by a great deal. Read the article, it's very informative.
That's got to be the reason some people are seeing it, and some aren't. Personally, I haven't experienced pinging at all, and I run 87 octane.
That's got to be the reason some people are seeing it, and some aren't. Personally, I haven't experienced pinging at all, and I run 87 octane.
08-08-2004, 05:05 PM
#58
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Okay, a couple of points:
* Remember, folks, this is a learning ECU. If you always use Sunoco 94 and then run a tank of 87, it wouldn't suprise me to learn there was some pinging at hard throttle. If you do switch from very high octane to 87, be careful with it for the first tank.
* Due to the nature of a naturally aspirated rotary engine, a lower-octane (quicker-igniting) fuel will result in increased fuel efficiecy, since the flame front will move more rapidly through the combustion chamber and burn the fuel more completely. Of course, with less unburned fuel and a lower ignition resisitance, there is an increased risk of pre-detonation. For the most part, though, N/A rotaries traditionally more powerfully/more efficiently on lower octane gas.
If you use low octane regularly, and don't experience any pinging, you may find you have an increase in efficiency or performance . . .
Peace
policy
* Remember, folks, this is a learning ECU. If you always use Sunoco 94 and then run a tank of 87, it wouldn't suprise me to learn there was some pinging at hard throttle. If you do switch from very high octane to 87, be careful with it for the first tank.
* Due to the nature of a naturally aspirated rotary engine, a lower-octane (quicker-igniting) fuel will result in increased fuel efficiecy, since the flame front will move more rapidly through the combustion chamber and burn the fuel more completely. Of course, with less unburned fuel and a lower ignition resisitance, there is an increased risk of pre-detonation. For the most part, though, N/A rotaries traditionally more powerfully/more efficiently on lower octane gas.
If you use low octane regularly, and don't experience any pinging, you may find you have an increase in efficiency or performance . . .
Peace
policy
08-08-2004, 08:45 PM
#59
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Policyvote,
I've had dramatically improved mileage going from 93 to 87 octane. My car has only 4k miles on it. Is it safe for me to continue with this 87 octane? I have no decrease in performance and I have no detonation.
Steve
I've had dramatically improved mileage going from 93 to 87 octane. My car has only 4k miles on it. Is it safe for me to continue with this 87 octane? I have no decrease in performance and I have no detonation.
Steve
08-08-2004, 09:28 PM
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Absolutely. Mazda recommends 91, but I am pretty sure the documentation says that 87 is the absolute low end. Believe it or not, old N/A rotary racers used to use 86 and 85 in their engines due to the increase in power/economy.
Of course, any sort of forced induction on a rotary immediately required the highest octane available. Detonation under boost on a rotary is bad news.
Peace
policy
Of course, any sort of forced induction on a rotary immediately required the highest octane available. Detonation under boost on a rotary is bad news.
Peace
policy
08-08-2004, 09:55 PM
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Originally Posted by policyvote
Okay, a couple of points:
* Remember, folks, this is a learning ECU. If you always use Sunoco 94 and then run a tank of 87, it wouldn't suprise me to learn there was some pinging at hard throttle. If you do switch from very high octane to 87, be careful with it for the first tank.
* Remember, folks, this is a learning ECU. If you always use Sunoco 94 and then run a tank of 87, it wouldn't suprise me to learn there was some pinging at hard throttle. If you do switch from very high octane to 87, be careful with it for the first tank.
when ur car is a daily driver..u know what sounds sounds it makes..and when something sounds abnormal...
08-08-2004, 10:14 PM
#63
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Like I said, I'm not denying that pinging might occur. Given the discrepancies in altitude, temperature, barometrice pressure, and (apparently) MAF calibration, everyone's A/F ratio is going to vary a little. If you're running a little leaner than most, and your ECU assumes what's coming into the tank is the usual 93, and you dump 87 in it and run up to redline at WOT . . . I can definitely see some pinging going down.
Peace
policy
Peace
policy
08-09-2004, 01:49 PM
#64
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True story. I filled up with 87 ONCE, and it was on a highway trip. During the trip I made some fast acceleration passes and I had some pinging type engine noise. I have never heard that before. I ran that tank out, filled up with 93 and drove home later that day. About two hours into the return trip, I made some more fast acceleration passes. Wammo! No more engine noise. Moral of the story, stay with 93!!!
08-09-2004, 04:36 PM
#65
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Originally Posted by LBrx8fan
True story. I filled up with 87 ONCE, and it was on a highway trip. During the trip I made some fast acceleration passes and I had some pinging type engine noise. I have never heard that before. I ran that tank out, filled up with 93 and drove home later that day. About two hours into the return trip, I made some more fast acceleration passes. Wammo! No more engine noise. Moral of the story, stay with 93!!!
u copying my story?? lol
08-10-2004, 05:25 PM
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Chevron 94, Supreme Plus.
Cost me damn near $50 bucks to fill my tank yesterday (first fill)... 99.5 cents per litre (3.3 Litres per US Gallon). So that's like, 3.33 per gallon Canadian.
Cost me damn near $50 bucks to fill my tank yesterday (first fill)... 99.5 cents per litre (3.3 Litres per US Gallon). So that's like, 3.33 per gallon Canadian.
Last edited by ÜberJumper; 08-10-2004 at 05:28 PM.
08-29-2004, 12:24 AM
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Originally Posted by rotayking
The only reason mazda wants you to get premium fuel is to reduce the chances of knocking(fuel combustion from compression). That is alll
That is the ONLY reason there needs to be!
08-29-2004, 10:54 PM
#68
look MA! No PISTONS!!!!
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what does a rotary pinging exactly sound like???
I get a weird rattling like sound sometimes when I'm WOT but I've been running 87 for almost 3 months now & this happens on & off... not sure what the deal is...
I get a weird rattling like sound sometimes when I'm WOT but I've been running 87 for almost 3 months now & this happens on & off... not sure what the deal is...
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