YAGT: Which do you buy/prefer?

[rivan]

While getting gas this morning, I noticed the price at the pump for midgrade was what I paid a couple weeks ago for basic unleaded. I almost got the midgrade without having any reason to do so, other than it sounds like an 'upgrade' for the same price I paid last time. My car doesn't (I think?) require it...

So I'm curious about the rest of you...

 

[Asharus]

I have a Hess card so I always shop at Hess for gas. The weird thing lately is that 87 is 30 cents cheaper than 89 and 91 is 10 cents more than 89. It used to only have a 10 cent difference between each grade. Anyone know why?

My daily beater 86 325es takes 87, but my 98 540i takes 89, and I'm a little pissed that it's 30 cents more than 87.

 

[SynthDude2001]

I drive a supercharged car, so always premium (93) for me...

 

[TheSlamma]

Adding Moonpie's to a beat down subject huh

 

[EngenZerO]

my g35 requires premium, so i put premium in my car...

 

[acemcmac]

Originally posted by: EngenZerO
my g35 requires premium, so i put premium in my car...

Same here. Mustang is rated for 87, so I put 87 in. Anyone who puts in higher octane than they are required to by the manufacturer (or the manufacturer of the turbo/supercharger) is a damend fool.

 

[acemcmac]

BTW, 100 Octane is 7.99/gal locally.

 

[Syrch]

my truck (F-150) will get ruined if i put anything in than the low grade stuff...says so in the manual and has been proven. My dad (the previous owner) used to put the high octane in every once in a while and I had to replace to coils early...the bastard! Oh well I love the truck even though i need knew ball bearings in the front.

 

[EngenZerO]

Originally posted by: acemcmac

Originally posted by: EngenZerO
my g35 requires premium, so i put premium in my car...

Same here. Mustang is rated for 87, so I put 87 in. Anyone who puts in higher octane than they are required to by the manufacturer (or the manufacturer of the turbo/supercharger) is a damend fool.

i totally agree... i put gas based on the specs set forth by the manurfacturer...

 

[nakedfrog]

91 in the turbo, 87 in the other cars.

 

[Fenixgoon]

depends on the vehicle.. if i drive my mom's van - regular, as that what the MFR suggests

if i'm in the pasast my sisters and i share - premium, what VW suggests

 

[lokiju]

Basic
No
No

But for my motorcycle I always use premium.

 

[Pabster]

Originally posted by: acemcmac
Same here. Mustang is rated for 87, so I put 87 in. Anyone who puts in higher octane than they are required to by the manufacturer (or the manufacturer of the turbo/supercharger) is a damend fool.

Not necessarily. I run 91 and 93 because the lower grades are full of water and run like crap.
This is especially true at smaller stations that don't move large volumes of fuel daily.

I could "get by" with 89, of course.

 

[ArchCenturion]

Sometimes I can't tell if you are stupid, or just plain retarded.

The only reason to get a higher grade (octane fuel) is if your car has a higher compression ratio and pings because of pre-detonations. There are charts and graphs, that can show you where the maximum efficiency/power/economy are and manufacturers will often try to build their engines around that point.

Adding supercharger, or a turbo supercharger changes the pressure/tempature in your cylinders so you will often need to upgrade your fuel.

The numbers you see ie 87, 89, 91 have nothing to do with watered down, or dirtier. It is simply the octane rating, how much pressure/temperature the gas can take before it self detonates.

If you are getting watered down gas, no matter what the octane rating, you are fvcked.

On a side note, you can mix gasoline, ie mix 87 with 89, to achieve a cheaper fuel mixture. If your car pings at 87, try mixing in some 89 if you are going to be doing some mountain driving, where your car will struggle ie pedal to the metal, put in a higher octane rated fuel. It is better for your engine not to ping. The higer octane fuel also does not burn as clean, and will emit more greenhouse gases ie co2, nox, co, etc

 

[Zenmervolt]

93 in the 951, more if I dial in more boost.
87 in the Mustang.

ZV

 

[Zenmervolt]

Originally posted by: ArchCenturion
Adding supercharger, or a turbo supercharger changes the compression ratio of your engine

Wrong. The compression ratio is a static measurement based on a comparison of cylinder volume when the piston is at bottom dead center versus when it is at top dead center. The compression ratio doesn't change one bit by adding forced induction. The total cylinder pressure changes but the compression ratio itself remains constant.

Compression ratio per-se does not really impact necessary octane, rather it's overall maximum cylinder pressure (along with combustion chamber design, spark plug heat range, timing curve, etc). The reason that most novices associate compression ratio with octane requirements is that, all else in an engine being equal, a higher compression ratio will generate higher overall maximum cylinder pressure.

As an example, the compression ratio of my 951 (which runs 15 PSI of boost) is 8:1. The compression ratio of my Mustang (naturally aspirated) is 9.8:1. The 951 obviously runs higher cylinder pressures, but it has a lower compression ratio. In fact, nearly all (I can't think of any that don't, but there may be one or two) factory turbocharged engines have lower compression ratios than their naturally-aspirated counterparts.

ZV

 

[Pabster]

Originally posted by: ArchCenturion
If you are getting watered down gas, no matter what the octane rating, you are fvcked.

That's about the only point I'll agree with.

 

[DaShen]

I could run on Plus, but I choose to pump premium gas. I also only use Chevron gas because I have never had a problem with it.

 

[vi edit]

I put in 87 because that's all the truck needs. As far as price, I'll pay more for "pure" gas over the 10% ethanol because I get about 10% better milage out of the regular. Plus I don't have to worry about some of the speculation and fear of ethanol corroding lines and hoses.

 

[azev]

Originally posted by: Syrch
my truck (F-150) will get ruined if i put anything in than the low grade stuff...says so in the manual and has been proven. My dad (the previous owner) used to put the high octane in every once in a while and I had to replace to coils early...the bastard! Oh well I love the truck even though i need knew ball bearings in the front.

That is odd, my brother has a 98 F150, with a regular gas, we are having some serious pinging problem when pulling a 5K lbs trailer. Filling premium gas solved that issues, and the truk feels much more responsive.

 

[Feldenak]

87 octane at the cheapest place I happen to drive by while needing gas.

 

[nakedfrog]

Originally posted by: azev

Originally posted by: Syrch
my truck (F-150) will get ruined if i put anything in than the low grade stuff...says so in the manual and has been proven. My dad (the previous owner) used to put the high octane in every once in a while and I had to replace to coils early...the bastard! Oh well I love the truck even though i need knew ball bearings in the front.

That is odd, my brother has a 98 F150, with a regular gas, we are having some serious pinging problem when pulling a 5K lbs trailer. Filling premium gas solved that issues, and the truk feels much more responsive.

Maybe the timing is off?

 

[FoBoT]

what are "Viking ranges" ?