: STS Octane



IloveSTS
12-24-12, 12:41 AM
Hi-

I drive a 2005 STS with 91,700 miles. I have used premium fuel with it the entire lifetime of the car. I have heard, not in a direct question, that premium fuel is not required. Is this true? I drive the car gently on a low-traffic commute, and I don't put much effort on the engine. I use 91 octane, and was wondering if 87 was viable.


Thanks!

orange57
12-24-12, 01:07 AM
Directly from the owners manual of a 2005. So use of mid grade or regular is acceptable, but will lack some performance.

http://photos.imageevent.com/orange57/cadi/websize/Octane.png

IloveSTS
12-24-12, 11:28 AM
Thanks!

EChas3
12-24-12, 02:59 PM
Use 'Top Tier' gas. If you notice ping or knock try 89 or a different brand. Premium may be overkill; some do not notice a difference.

curtc
12-24-12, 06:00 PM
I notice no difference between 87 or 91

1BadCadSTS
12-24-12, 08:02 PM
I notice a difference under heavy acceleration between 89 and 93. Never put 87 in mine and never will.

curtc
12-24-12, 08:09 PM
I notice a difference under heavy acceleration between 89 and 93. Never put 87 in mine and never will.

I use 89 95% of the time as it is usually the same price as 87...She gets 91 when she gets her Techron.

Was just stating as I have used 87 and noticed no difference.

Mullah88
12-24-12, 09:10 PM
i use premium but i still hear a loud knocking every time??

curtc
12-24-12, 10:44 PM
i use premium but i still hear a loud knocking every time??

Those 3.6's like to make their presence known...Make sure the oil is always full.

DarkMingBlueSTS
12-24-12, 11:34 PM
i use premium but i still hear a loud knocking every time??

Loud knocking every time you what?

Mullah88
12-25-12, 02:45 AM
....every time i drive the car, let the engine run...its more of a air puffing (or air being sucked in) sound coming from the right side of the hood, ill make a youtube video of it tomorrow if i get the time

Platinum06
12-25-12, 03:02 AM
I was using 89 for a while when the price of gas was mid $4.00 range. When it came down i went back to 93 and it was noticeably smoother and quicker.

ddalder
12-25-12, 03:22 PM
Where I live, 91 octane is about $0.10/L more than 87. I fill up about every 10 days with a fill averaging about 55L. So, based on this, I figure the annual difference between using 87 and 91 is about $200.00. Not enough that I care. I do believe, although not necessary, I get better performance.

Aurora5000
12-25-12, 04:25 PM
I use 87 for 6 years