1 part 87 + 2 parts 93 = 91
 

I don't know what the deal is, but the price of regular has been falling a lot faster than premium, resulting in a 40-60 cent differential between 87 and 93 octane. So, I save about $2 a tank by swiping my credit card twice. Does anyone else do this?

octanes do not mix on a a proportional scale.

50% 87 and 50% 93 is not 90. its more like 92.

afaik.

and no i dont do that.

the octane listed is at least the rating given, it also might be higher.

I use shell v-power.

One time a hurricane stopped the supply of fuel for over a week and I had to use 89. I heard some predetonation going on around the 6,000 RPM mark. Didn't get above 3,000 RPM after that until 93 was sold again.

I have a 14 cent differential here. $1.91 regular and $2.05 premium

you mean 2.91 regular and 3.05 premium?

no way are you paying $2/gallon for premium. thats just crazy.

Would you care to elaborate? If you were combining isooctane and heptane mixtures, then mixing octanes most certainly would be proportional -- by definition. I suppose actual mixtures might vary somewhat, but I wouldn't think it would be that much.

To save 2$? Lol? Are you that cheap?

uh.... thats amazing. im paying $3.03 for premium, and it was at$ 4.50 ish a week ago

bwahaha rly tho

its cheap in texas, the gas station near me has regular for 1.90 and premium is like 2.13 or something.

im paying 2.40 for premium in the expensive island/tourist areas on the FL coast. I know inland a bit it can get down to 2.20ish for premi, under 2 for regular. FL ftw, cheap gas and 80 degrees in nov.

and im not going to go through that to save 2$. i could drive less agressively and save more than that if i wanted.

$2.36 is the average for regular in FL.

http://www.floridastategasprices.com/

https://www.rx8club.com/attachment.p...1&d=1225802311

$2 in 30 seconds? That's $120 an hour - tax free. Yep, I'm that cheap.

We have a .21 cent difference here in Ohio. Regular today was 1.97 :lol: . I wonder what will happen after the election settles down or if it has any effect.

Take care,

Brian

no effect. it will just keep going down

We're in recession and there is nothing can stop this.

I'm serious about my prices lol. It dropped big time and fast. The most I ever paid was 4.05 for premium. Then one day it cost $22 for 3/4 of a tank instead of $45

wow i guess california is just expensive on gas

^werd. I payed $5.05 last summer and am paying $3.09 right now... I'm definitely not complaining though :)

up here in davis/sacramento it's 2.29 for regular at chevron and shell and 2.49 for premium :)

$2.03 here in dallas

i wished i lived in davis now.. gas in Fremont, Union City, Hayward area is getting better. i only get 76 and the cheapest i got was 2.69 for 87 and 2.89 for 91. they are usually 20cents apart

i live in danvill and the cheapest i gotten 91 is $2.99 today..

Uhh... its 240/hr, and i guess if you cant multiply, you prob dont make much from your normal job eh?

but aside from that, people wanna complain about gas, i bet any time you've gone out for lunch you could save more than 2$ by drinking water instead of soda, by ordering a different meal, or by being a bad tipper, but do you?

Or you could not go out for lunch and make your own lunch for even cheaper.. but nope, it's better to skimp out on good quality gas for your car, I mean hell, in the event something goes wrong, at least there'll be plenty of money saved from those 2$ to pay for repairs.:yelrotflm

I guess I can't keep track of enough variables to make $240/hr. :wallbash:

I do usually skip the drink -- no reason to pay for sugar I'm better off without.

91 IS the recommended octane rating.

Yes but 89 and 93 have different densities and don't exactly instantly mix, so the engine could suddenly get an influx of 89 and then get an influx of 93, and then 91, etc..

However I'm just yanking your chain, it probably doesn't make much difference IMO, I just personally don't really see a point to saving 2$ :p:

i live in santa ana, and 91 is 2.75

I pay around $2.70 right now for 93 in south louisiana

I worry about the mixing. I recently filled my Honda and added Stabil because it gets driven very little. I put the Stabil in first, then found a nice bumpy and twisty road to mix it before parking it.

Back closer to the original concept of this thread. Remember the old Sunoco custom blend pumps? With eight grades at their ratings of 190 through 260? They didn't actually have eight tanks underground. Just two, and the right mix was blended at the pump. I've always wondered if current stations with 87-89-93 have three tanks, or just two and a mixer.

Ken

It may depend on the station. There's a Sunoco station near me that used to be a Mobil station -- and it has 87-89-93. Three tanks there, I think. OTOH, there are a couple of other stations I know of that have 87-89-91-93. I'd bet they have two tanks and mix.

So that raises the question: How do they fill up those 89 tanks? Do they bring a tanker full of 89, or do they mix two parts 87 and 1 part 93?

I can one up you.. I pulled in to a Shell station around Orlando and was presented with the following choices:

87-Regular Unleaded
88-Super Regular Unleaded
89-Premium Regular Unleaded
91-Super Plus Unleaded
92-Premium Plus Unleaded
93-Super Premium Unleaded

I should have taken a pic now that I think about it.. I don't know why they skipped 90 though.. but oh well, all were within 2 cents of each other in terms of price btw..

i got excited i saw 2.99 for premium at a mobile...

and on the side i hate those gas stations the show a price on the big boards. but when you go inside its for cash only happen to anyone else?

I haven't seen cash-only prices for a long time, like at least 20 years. I remember when one brand would give a 4 cent per gallon discount for cash. Must have driven the pump jockeys nuts.

I've gotten tricked by stations that show three prices, but one is the cigarette price and the one you'd think was for premium is for 89.

FWIW, I just filled up with 93 at an Exxon station for $2.649 per gallon. First time in quite a while that I've gotten out of a gas station for less than $30.

Ken