regular grade vs. premium??
Le Mans Master
Joined: Dec 2004
Posts: 7,475
Likes: 2
From: Austin TX
St. Jude Donor '07
For some of the gas stations in the smaller towns in New Mexico, the premium octane is 90. I filled up with that and had no problems whatsoever.
I always fill up with super unleaded. As was stated before, the cost savings of going with the lower octanes is negligible. at only 10-20 cents cheaper, even if you filled up your entire tank, you'd be saving a maximum of $2.00 - $4.00 per fill up. So if you fill up 3 times a month, you would've only saved $6.00 to $12.00 by going with the cheaper stuff. It's worth it to me to just get the good stuff.
I always fill up with super unleaded. As was stated before, the cost savings of going with the lower octanes is negligible. at only 10-20 cents cheaper, even if you filled up your entire tank, you'd be saving a maximum of $2.00 - $4.00 per fill up. So if you fill up 3 times a month, you would've only saved $6.00 to $12.00 by going with the cheaper stuff. It's worth it to me to just get the good stuff.
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
ZERO production vehicles, (except for rare stuff) will ever require above 91 octane per the manufacturer.
91 octane is the highest offered in CA, and that limits the design. In the same way our strict smog rules affect all 50 states.
91 octane is the highest offered in CA, and that limits the design. In the same way our strict smog rules affect all 50 states.
Team Owner
Joined: Sep 2002
Posts: 22,209
Likes: 12
From: OBAMA IS HITLER
Originally Posted by CentralCoaster
ZERO production vehicles, (except for rare stuff) will ever require above 91 octane per the manufacturer.
91 octane is the highest offered in CA, and that limits the design. In the same way our strict smog rules affect all 50 states.
91 octane is the highest offered in CA, and that limits the design. In the same way our strict smog rules affect all 50 states.
Melting Slicks
Joined: May 2001
Posts: 2,700
Likes: 3
From: Lebanon KY
Originally Posted by Hot Rod 90
midgrade is 89. premium is 91 maybe 92. some folks think premium is 93 and 94, but that should really be called ultra super premium and is overkill imo for an LT1 engine......... ostensibly. as was stated earlier, you need a scanner/analyzer to look at knock & timing retard.
here's the breakdown i would generally go with:
'84-85: 87 octane
86-89: 87, or 89 octane max
90/91: 89, or 91 octane max
92-96 LT1: 91 or 92 octane
as has been said, each car may differe a bit. you'd have to test with an engine analyzer to really know the lowest octane you can run --- for best results.
here's the breakdown i would generally go with:
'84-85: 87 octane
86-89: 87, or 89 octane max
90/91: 89, or 91 octane max
92-96 LT1: 91 or 92 octane
as has been said, each car may differe a bit. you'd have to test with an engine analyzer to really know the lowest octane you can run --- for best results.
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Originally Posted by corvettemaster
i gotta question. i have an 86 that i run nothing but premium in (and around here, that's 93 octane). i don't care about the extra 20 cents. but according to your chart it says 87 or 89 max? am i actually losing power by going with the higher grade?
Not really, but I'd stop using 93 unless you just like tipping the CEO of Exxon for every gallon you buy. I mean, he really could use some more money.
Melting Slicks
Joined: May 2001
Posts: 2,700
Likes: 3
From: Lebanon KY
well i run a 150 shot of nitrous at the track quite often, so it'd be too much of a pain trying to run 89 regularly and then trying to get 93 in it for the track. i was just curious as to whether it was hurting power any during everyday driving. thanks 
