ortcele

What difference does the octane rating make? On my gas cap it recommends BP also known as Amoco. Has any one noticed a difference when using Amoco compared to other brands? When I use 93 oct I feel that the engine runs and sounds smother as compared to when I use 87 oct. But I’m not sure if it gives me better performance or better gas mileage? I’m currently running a 2006 stock v6.

hamidlmt

Generally, stick with 87 octane, unless you're experiencing some engine knock (then, try the next grade up). I'd only use a higher octane if you have a tune that can take advantage of it.

amystery2u

I use 89 Octane. I switched from 87 because I went to the 17" rims and my mpg went down. When I switched I noticed better mileage and performance.

As far as using BP or Amoco, here in TN they are the most expensive so I usually fill up at Wal-Mart or Kangaroo. I don't notice a difference.

Puleo76

i found shell gives me the best mpg and bp gives me horrible mpg... 93 all the way

blackfoot

my owners manual says knock at idle is normal.. lol i was like NO ITS NOT. lol

your engines dont need an higher octane unless your using a power adder of significant addedness. lol (great choice of word) higher octane just means that it takes more for it to burn (which wards off pre-ignition and detonation) and it burns cleaner

djl0657

It is my understanding that running on higher octane then is defined by the manufacturer is just wasting money. Unless you have a specific need or performance additions that warrant higher octane, the car should run fine on 87 octane. The computer and fuel delivery system is programmed to run at a certain octane, if the manual calls for 87, then 87 should do the job.

8cd03gro

The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites. When gas ignites by compression rather than because of the spark from the spark plug, it causes knocking in the engine. Knocking can damage an engine, so it is not something you want to have happening. Lower-octane gas (like 87 octane gasoline) can handle the least amount of compression before igniting.

if you are going to be running your engine hard (therefore hot) go with the highest octane possible because it will be safer and will have a much smaller tendency to knock. I personally run 91 every day because my local station doesnt have 93 and my parents pay for my gas

if the extra cash is no big deal then run the highest octane you can all the time, but if it is really running down the bank account, run whatever.

djl0657

Wish my parents bought my gas, but hey, I'm 54 so I guess that is out of the question.

My point was that you should run the LOWEST octane that you can without knocking. My 05 runs great on 87 and I believe most vehicles are programmed to run on 87. I read about the performance modifications on this forum and I imagine that some of the computer tuning jobs require higher octane. If your car is designed to run on 87 and you run higher, you are just wasting the extra money as there are no additional performance improvements (unless the car is knocking, which is rare compared to the performance cars we ran in the sixties).

Badash

The manual recommends 87 octane, the problem is the quality of the gas.

8cd03gro

exactly, the quality is lower with lower octane gas most of the time. thats whyi said run the highest you can while still staying in your budget. If all you can afford to buy without having to change your cash flow is 87, dont worry about it it is completely fine. I was just saying it doesnt hurt to run higher quality gas. It's like buying dole fruit pops or some off brand popsicle. The dole is just a tiny bit better, but man if you can afford it... get that strawberry dole baby


oh you know you love that analogy.