Premium Gas
#1
#2
#4
I read an interesting article on the true octane rating of gasoline mixed with ethanol (heck, it might've been in Car and Driver) that basically stated that if gas is mixed with the max allowable ethanol (10% or 15%?) then the 87 octane rating would effectively be 91-92 when taking into consideration the ethanol's higher octane rating. I guess it was a weighted average. But of course energy content by volume is reduced too.
So, I guess what I'm trying to say is, you should fill up with whatever the manual calls for (91 I'm guessing).
But if you're in a pinch I doubt it would cause any knocking or damage by putting in a lesser fuel (just maybe power loss and lower mileage?).
I have an '05 S60 T5 and use 89 because we're on a strict budget and every penny counts right now. I suppose when times get better I'll go back to filling it with 91, but I'm not at all worried that I'll do any damage with 89, and I wouldn't be horrifically scared to put 87 in it in a pinch. But I'll stick with 89 for now.
So, I guess what I'm trying to say is, you should fill up with whatever the manual calls for (91 I'm guessing).
But if you're in a pinch I doubt it would cause any knocking or damage by putting in a lesser fuel (just maybe power loss and lower mileage?).
I have an '05 S60 T5 and use 89 because we're on a strict budget and every penny counts right now. I suppose when times get better I'll go back to filling it with 91, but I'm not at all worried that I'll do any damage with 89, and I wouldn't be horrifically scared to put 87 in it in a pinch. But I'll stick with 89 for now.
Last edited by mhphoto; 06-29-2012 at 11:08 PM.
#5
extended use of "lesser quality" fuels have been shown to harden and damage fuel system components such as lines and fuel pump housings. in the manual you will also notice that is recommends premium fuel AND it says no more than 10% ethanol. so they factor all of this in while coming up with their octane requirements but the real reason for the premium fuel is not the octane believe it or not. lesser quality fuels have more gunk in them, this gunk builds up and gets hot with regular combustion of your engine. over time these deposits build up so much that they bake all your engine parts such at valves and pistons which is not a problem in most engines. but high compression turbocharged engines get much much hotter than regular compression, normally aspirated cars do.
So basically if you can afford a nice car buy nice fuel, if not, if you can't afford the fuel buy a Honda.
So basically if you can afford a nice car buy nice fuel, if not, if you can't afford the fuel buy a Honda.
Last edited by rspi; 06-30-2012 at 08:39 PM. Reason: typo
#6
extended use of "lesser quality" fuels have been shown to harden and damage fuel system components such as lines and fuel pump housings. in the manual you will also notice that is recommends premium fuel AND it says no more than 10% ethanol. so they factor all of this in while coming up with their octane requirements but the real reason for the premium fuel is not the octane believe it or not. lesser quality fuels have more gunk in them, this gunk builds up and gets hot with regular combustion of your engine. over time these deposits build up so much that they bake all your engine parts such at valves and pistons which is not a problem in most engines. but high compression turbocharged engines get much mutch hotter than regular compression, normally aspirated cars do.
so basically if you can afford a nice car buy nice fuel, if not, if you can't afford the fuel buy a Honda.
so basically if you can afford a nice car buy nice fuel, if not, if you can't afford the fuel buy a Honda.
#7
I'm not buying that what you call "lesser" fuels have more "gunk" in them. Octane ratings are just that, a rating of the fuel's octane, not a rating of quality. You could make the "gunk" argument for different brands of gas, but just because a fuel has a higher octane rating absolutely says nothing of the quality of the fuel. And as far as the ethanol hardening fuel components, you're right, but I should hope that with the government pushing ethanol on us for the past years, manufacturers (especially premium brands) would find a way to not have the most widely available mix of fuel eat the cars they sell from the inside.
everything I said about the fuel and how it reacts in our Volvos is from the Volvo manual and from multiple Volvo techs, much of which I am apprehensive to believe as well.
for me, my cars premium has been by far the best, I've tried all the different fuels and even pure ethanol and if you can get between a 91-93 octane the car simply responds better, sounds better and the exhaust burns cleaner whereas other fuels cause ping and knock, the car chugs and is hard to start but it runs none the less.
oh and don't do as some suggested, to buy cheap fuel and add octane boosters. they have been shown to actually lower your octane of the fuel! there have been some surprising studies you might be well interested in looking up.
#8
I alway buy 91+ unless I'm taking a road trip. Just economics for me. I drove my car (recently) will all types of fuel and all octanes and when putting down the highway at 70 mph, using an average of 50 hp, 87 octane got the same mileage as the 93 pure gas (no ethonal). So, while my ship is taking on water, my car will get 87 when I'm just dumping it with a few hours.
Then again, I don't have a $43,000 new S60 R.
Then again, I don't have a $43,000 new S60 R.
#10
all the nitrogen does is resist thermal expansion do to friction. you still need to monitor your tire pressure. and since most of us don't have nitrogen tanks laying around it's in my opinion anyway better to use regular air. (of course I check my tire pressure at every fill up lol)
#12
well in order to achieve the higher octane the crude oil has to be processed more, much like a good vodka is distilled more times than a lesser quality one. the octane is because it's a higher concentration of basically what we know as "fuel" so one can conclude that it's a purer form aka less gunk.
everything I said about the fuel and how it reacts in our Volvos is from the Volvo manual and from multiple Volvo techs, much of which I am apprehensive to believe as well.
for me, my cars premium has been by far the best, I've tried all the different fuels and even pure ethanol and if you can get between a 91-93 octane the car simply responds better, sounds better and the exhaust burns cleaner whereas other fuels cause ping and knock, the car chugs and is hard to start but it runs none the less.
oh and don't do as some suggested, to buy cheap fuel and add octane boosters. they have been shown to actually lower your octane of the fuel! there have been some surprising studies you might be well interested in looking up.
everything I said about the fuel and how it reacts in our Volvos is from the Volvo manual and from multiple Volvo techs, much of which I am apprehensive to believe as well.
for me, my cars premium has been by far the best, I've tried all the different fuels and even pure ethanol and if you can get between a 91-93 octane the car simply responds better, sounds better and the exhaust burns cleaner whereas other fuels cause ping and knock, the car chugs and is hard to start but it runs none the less.
oh and don't do as some suggested, to buy cheap fuel and add octane boosters. they have been shown to actually lower your octane of the fuel! there have been some surprising studies you might be well interested in looking up.
#13
#14
Why do these octane threads always turn into mis-information flaming matches?
See post #22
https://volvoforums.com/forum/volvo-...n-51764/page3/
In a nutshell these cars have knock-sensors that allow them to run anything from regular to premium; the engines (per owner's manual) are designed to run on premium and that's where you'll max performance and gas mileage. I always use mid-grade (91 octane) in mine; seems the best trade-off between price and performance to me.
OK, flame on..
See post #22
https://volvoforums.com/forum/volvo-...n-51764/page3/
In a nutshell these cars have knock-sensors that allow them to run anything from regular to premium; the engines (per owner's manual) are designed to run on premium and that's where you'll max performance and gas mileage. I always use mid-grade (91 octane) in mine; seems the best trade-off between price and performance to me.
OK, flame on..
#15
Why do these octane threads always turn into mis-information flaming matches?
See post #22
https://volvoforums.com/forum/volvo-...n-51764/page3/
In a nutshell these cars have knock-sensors that allow them to run anything from regular to premium; the engines (per owner's manual) are designed to run on premium and that's where you'll max performance and gas mileage. I always use mid-grade (91 octane) in mine; seems the best trade-off between price and performance to me.
OK, flame on..
See post #22
https://volvoforums.com/forum/volvo-...n-51764/page3/
In a nutshell these cars have knock-sensors that allow them to run anything from regular to premium; the engines (per owner's manual) are designed to run on premium and that's where you'll max performance and gas mileage. I always use mid-grade (91 octane) in mine; seems the best trade-off between price and performance to me.
OK, flame on..
#16
Misleading info
I have read everyones posts and it sems a lot of you dont know what you are talking about. Using 87 octane vs 93 ocatane does not change your gas milieage. The knock sensors is a reality and would prevent serious damage to the engine if only using 87 octane. A reality is a human would run better on water only but then no one would drink beer . I think I will stick with premium with a mid rade fill up every couple of tanks. The 20 cents per gallon more seems worth it!
#17
So with knock sensors, the ECM will advance the spark until knock is induced, then back it off till it goes away. Your engine is constantly on the threshold of knocking. Does this continuously for all driving conditions/loads/etc. Again this is where you get max power/efficiency.
#18
#19
Actually, pure nitrogen does more than just resist thermal expansion. Due to its larger molecule, it doesn't permeate the rubber as easily as the oxygen molecule does and therefore doesn't leak down as easily as just plain old air does...even though air is 78% nitrogen anyway. Also, pure nitrogen doesn't cause corrosion from moisture like plain old air does. Not much of a problem either way unless you have a tire pressure monitoring system. Corroded contact in any of those tire sensors can be a real pain.
#20
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