Gas Octane Ratings
#1
06-13-2008, 04:07 AM
Join Date: Mar 2008
Location: Auckland, New Zealand
Posts: 3,286
Gas Octane Ratings
Curious to know, what octane rating are you Blazer guys using? And what ratings are available. Do they differ around the US & Canada?
Here in New Zealand we have 91 & 95.
Reason for this question is thatI was at the Chevy specialist this afternoon to price a tune up for the Blazer.In discussion I mentionedI was running 91 petrol. (91 is the cheaper).
They told me that 91 was ok but I shouldrather change to the higher rating of 95 & I should get more kilometres (as well as better performance) from each litre of fuel. So the increased cost of the higher grade should be offset by more kms.
Currently I get around 320km from a tankfull of +-52 litres so I'll run the next 3 tanks on 95 & see what difference it makes.
Here in New Zealand we have 91 & 95.
Reason for this question is thatI was at the Chevy specialist this afternoon to price a tune up for the Blazer.In discussion I mentionedI was running 91 petrol. (91 is the cheaper).
They told me that 91 was ok but I shouldrather change to the higher rating of 95 & I should get more kilometres (as well as better performance) from each litre of fuel. So the increased cost of the higher grade should be offset by more kms.
Currently I get around 320km from a tankfull of +-52 litres so I'll run the next 3 tanks on 95 & see what difference it makes.
#2
06-13-2008, 07:15 AM
RE: Gas Octane Ratings
Um... No. Your efficiency will decrease. The fuel's octane rating is a direct relationship to a fuels ability to withstand predetonation. As such, it is burning slower. Unless you have a specific need for higher octane fuel (high static compression ratio or high dynamic compression ratio - supercharged/turbo), you will not see added benefits of running higher octane fuel. With the relatively low compression ratio of the 4.3L v6, you do not need to run high octane fuels.
The lowest octane rating around me is 87 octane with 89 and 91/93 available. The 4.3L is made to run on 87 octane fuel. If you have high levels of carbon built up in the combustion chamber (time for seafoam), then you may see a benefit from running a higher octane fuel as carbon buildup increases the compression ratio as well as creates hot spots in the combustion chamber which can cause detonation. If higher octane fuel increases your mileage, then that is signs that point straight at a carbon buildup in the combustion chambers that should be remedied.
The lowest octane rating around me is 87 octane with 89 and 91/93 available. The 4.3L is made to run on 87 octane fuel. If you have high levels of carbon built up in the combustion chamber (time for seafoam), then you may see a benefit from running a higher octane fuel as carbon buildup increases the compression ratio as well as creates hot spots in the combustion chamber which can cause detonation. If higher octane fuel increases your mileage, then that is signs that point straight at a carbon buildup in the combustion chambers that should be remedied.
#3
06-13-2008, 11:30 PM
RE: Gas Octane Ratings
ORIGINAL: swartlkk
Um... No. Your efficiency will decrease. The fuel's octane rating is a direct relationship to a fuels ability to withstand predetonation. As such, it is burning slower. Unless you have a specific need for higher octane fuel (high static compression ratio or high dynamic compression ratio - supercharged/turbo), you will not see added benefits of running higher octane fuel. With the relatively low compression ratio of the 4.3L v6, you do not need to run high octane fuels.
The lowest octane rating around me is 87 octane with 89 and 91/93 available. The 4.3L is made to run on 87 octane fuel. If you have high levels of carbon built up in the combustion chamber (time for seafoam), then you may see a benefit from running a higher octane fuel as carbon buildup increases the compression ratio as well as creates hot spots in the combustion chamber which can cause detonation. If higher octane fuel increases your mileage, then that is signs that point straight at a carbon buildup in the combustion chambers that should be remedied.
Um... No. Your efficiency will decrease. The fuel's octane rating is a direct relationship to a fuels ability to withstand predetonation. As such, it is burning slower. Unless you have a specific need for higher octane fuel (high static compression ratio or high dynamic compression ratio - supercharged/turbo), you will not see added benefits of running higher octane fuel. With the relatively low compression ratio of the 4.3L v6, you do not need to run high octane fuels.
The lowest octane rating around me is 87 octane with 89 and 91/93 available. The 4.3L is made to run on 87 octane fuel. If you have high levels of carbon built up in the combustion chamber (time for seafoam), then you may see a benefit from running a higher octane fuel as carbon buildup increases the compression ratio as well as creates hot spots in the combustion chamber which can cause detonation. If higher octane fuel increases your mileage, then that is signs that point straight at a carbon buildup in the combustion chambers that should be remedied.
Couldn't have said it better myself. The lowest I've seen in the states is 85 in Colorado. I've always run 87 in mine, even in when I'm in CO.
#4
06-14-2008, 02:54 AM
Join Date: Mar 2008
Location: Auckland, New Zealand
Posts: 3,286
RE: Gas Octane Ratings
Thanks Kyle, I didn't quite know how true their statement wasbut my lack of knowledge on the subject allowed me to think that I should at least try it but yea, I'll stick to 91.
#7
06-24-2008, 02:30 PM
RE: Gas Octane Ratings
The octane numbers posted on the pumps can be a little specious. Here in the U.S. it is a formula derived by taking the 'research' octane value, adding the 'motor' octane value, and dividing for the 'average' (pump) octane value. Different countries use different formulas. Ken, in NZ your 91 octane is equivilant to our 87 octane which is recommended by Chevrolet.
#8
06-25-2008, 03:12 AM
Join Date: Mar 2008
Location: Auckland, New Zealand
Posts: 3,286
RE: Gas Octane Ratings
Thanks for that Richard. One wonders why things can't be standardised internationally.
#9
07-09-2008, 10:13 AM
RE: Gas Octane Ratings
95, 98 & Shell V-Power doing 99 Octane. My blazer gets 95 that is the most I can afford over here 
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