Gas Octane

[BlueHair]

A few weeks ago, my little brother mentioned to me that he always puts the lowest octane gas in his vehicles. He has this theory that the car companies and the oil companies are in bed together and the recommended octane is bullshit. According to him, it's like the hotdogs and buns. The bread companies make sure you have to buy two packages because one is not enough for one pack of hotdogs. Anyway, I decided to take his advice and start buying the lowest grade. My gas mileage went up nine percent. I though it must be an abberation, but it has been three tanks now with the same result. It seems like I remember reading somewhere that octane is not as important at higher elevations. Any truth to this?

[Lost Student]

Originally Posted by BlueHair

A few weeks ago, my little brother mentioned to me that he always puts the lowest octane gas in his vehicles. He has this theory that the car companies and the oil companies are in bed together and the recommended octane is bullshit. According to him, it's like the hotdogs and buns. The bread companies make sure you have to buy two packages because one is not enough for one pack of hotdogs. Anyway, I decided to take his advice and start buying the lowest grade. My gas mileage went up nine percent. I though it must be an abberation, but it has been three tanks now with the same result. It seems like I remember reading somewhere that octane is not as important at higher elevations. Any truth to this?

The higher the compression in your engine, the higher octane you need. A high octane number just means that the fuel will not detonate as easily under pressure. There shouldn't be any fuel advantage to using lower, though--just cost savings if your car's engine doesn't have a high enough compression ratio to need high octane.

OTOH, if it is a higher-compression engine, and you do not use high octane fuel, the engine management computer will alter ignition timing, which would reduce efficiency.

[ute4ever]

I use 87 octane in my Camry and average 33 mpg on long trips, which is higher than toyota.com advertises.

I just bought new tires, so maybe I'll get 34 now.

[TripletDaddy]

Originally Posted by BlueHair

A few weeks ago, my little brother mentioned to me that he always puts the lowest octane gas in his vehicles. He has this theory that the car companies and the oil companies are in bed together and the recommended octane is bullshit. According to him, it's like the hotdogs and buns. The bread companies make sure you have to buy two packages because one is not enough for one pack of hotdogs. Anyway, I decided to take his advice and start buying the lowest grade. My gas mileage went up nine percent. I though it must be an abberation, but it has been three tanks now with the same result. It seems like I remember reading somewhere that octane is not as important at higher elevations. Any truth to this?

First, your brother's theory is clearly wrong. Do you think car companies are benefiting from the record high cost of oil right now? Car companies are slashing prices, inventories sitting on lots for months on end, entire segments of auto-production have been scaled down drastically (SUVs, trucks), etc.. Car companies are happiest when oil is cheap and people feel like driving all over the place.

Second, octane only matters in two instances...if you drive a sports car or some higher-end vehicles (mercs, for example). Pretty much every other car can just use 87. If your manual calls for 87, it will make no difference to use a higher octane.

[MikeWaters]

Originally Posted by TripletDaddy

First, your brother's theory is clearly wrong. Do you think car companies are benefiting from the record high cost of oil right now? Car companies are slashing prices, inventories sitting on lots for months on end, entire segments of auto-production have been scaled down drastically (SUVs, trucks), etc.. Car companies are happiest when oil is cheap and people feel like driving all over the place.

Second, octane only matters in two instances...if you drive a sports car or some higher-end vehicles (mercs, for example). Pretty much every other car can just use 87. If your manual calls for 87, it will make no difference to use a higher octane.

companies like Toyota are benefitting in the USA. Non-innovative American companies are screwed.

[TripletDaddy]

Originally Posted by MikeWaters

companies like Toyota are benefitting in the USA. Non-innovative American companies are screwed.

You are obviously not a Toyota shareholder.

http://www.autoblog.com/2008/05/08/t...-drop-in-2008/

Toyota is faring better than its American counterparts, but everyone is losing money.

[MikeWaters]

http://www.forbes.com/markets/2008/0...markets03.html

[TripletDaddy]

I am confused by your link. It speaks to volume, not profit.

Maybe Toyota can release its 10K and focus solely on how many cars they sold in the US, but make no mention of cogs.

[Coach McGuirk]

I had a 96 ford ranger V6. I put the lowest octane gas in Utah for about 2 months. at the end of those two months my engine started pinging pretty badly. I took it to my mechanic who informed me to upgrade my octane. I did, ping went away. I think it matters.

[Surfah]

Octane most definitely matters.

In my speed racer tuning days I used to have a turbocharged rocket with octane specific programming for 89, 91, 93 and 100 octane fuel. It made a huge difference. And I'm talking 10HP from 89 to 93. And over 20HP on race fuel.

Like McGuirk said, if your engine is pinging then use a higher octane. Lots of cars recommend higher octane fuel. The ones you have to look for are ones that require higher octane fuel.

85 octane in Utah is a joke. Even worse is buying gas in Utah County during the winter. They oxygenate their gas during the winter. And it costs you probably 5 mpg.

Your gas station charging $4.00 a gallon for gas probably paid $3.99 for the gas he's selling you.