Rich deals with how much fuel gets in. Not how much gas mileage or anything. I dont think octane will change how "rich" something is on our (for the majority) pretty much stock engines. FI it might matter.

Youre fine at 87. You maybe able to get a mile per gallon more if that. What really matters more though is driving habits.

Do what ever is cheapest as long as its 87 and up

scott

 

Everyone in almost every recently made vehicle is "okay" at 87, but don't "do what ever is cheapest" cause if u follow that motto, ur going to end up paying for ur cheapenss in the long run (i don't mean with gas, but with everything else).

 

good point. just with gas is a good recommendation. cheapness in other products can cost u more in the long run

 

Anyone know the long term effects using 91 vs 89 vs 87?

 

Biggest effect is on your pocketbook.


Read the link given above - http://auto.howstuffworks.com/question90.htm

 

I have a still hidden in my back yard, so I just burn moonshine.

 

IT IS A TOTAL WASTE OF MONEY TO USE 89 -- TOTAL

 

In Iowa and Nebraska our 89 has 10% ethonal in it, because of that the states subsidize it so 89 is usually a couple of cents cheaper than 87... because of that I run 89 in my car, when I leave Iowa I generally run 87 honestly my milage really doesn't change that much..... so basically run the 87 unless you can get the 89 cheaper like I can....

 

Repeat:

RUNNING 89 MAKES NO DIFFERENCE IN YOUR CAR. IT DOES NOT IMPROVE ANYTHING.

 

Use higher octane, it won't hurt and we appreciate the extra revenue.

Thanks,

Exxon

 

^^^

 

Just so someone else reinforces it.


HIGHER OCTANE DOES NOT INCREASE PERFORMANCE.


In fact, 87 octane is MORE explosive than 93. Premium gasolines are necessary in high-compression or turbocharged motors due to the increased heat and pressure. Knock is this heat and pressure detonating the AF mixture before or after the appropriate time.

 

Our engines are 10.5:1 compression. Other cars with that kind of compression recommend 91 octane. Toyota only lists 87 so people won't freak out and to keep costs down (same with the motor and gear oil changes).

 

I think the point here is that it doesnt knock. If it aint broke, why fix it?

 

Just like debate on synthetic vs non-synthetic motor oil, putting in higher octane gasoline is really just for your peace of mind. Your engine will be happy with 87 and non-synthetic oil at regular service intervals.

Oct 27, 2005 - Mobil Exxon 3 quarter earnings soared to $10 bil and it became first ever public company with quarterly sales topping $100 bil.

I don't think we need to give them any more of our money than necessary, do you??

87

 

I use the cheapest 87 gasoline I can find

89 or 91 would be a waste of money

 

Yes, and the Prius runs 13:1 and still specifies 87 octane.

Neither engine is made for high performance. The fact that their compression is higher than previous engines is a result of improved combustion chamber design, not of any attempt at hot-rodding.

George

 

...improved combustion chamber design AND improved electronic controls and control algorythms. Both the valve timing and the ignition timing are under computer control to, among other things, allow the engine to make efficient use of a 10.5:1 compression ratio on 87 octane fuel...

 

"Just like debate on synthetic vs non-synthetic motor oil, putting in higher octane gasoline is really just for your peace of mind. Your engine will be happy with 87 and non-synthetic oil at regular service intervals."

Not to go off on a tangent but, using synthetic oil isn't just a piece of mind issue, it flows better at low temperatures. i.e. if you live in a cold climate, cold starts aren't as harsh

 

put 87 octane in your car, the only reason for a higher octane is for if your engine has a knock, if your engine knocks, you need a higher octane, (a light pinging noise, not a connecting rod or loose exhaust flange that makes weird noises.