: Get ready for a long thread...What fuel do you use?

Lev Blekher
11-06-10, 05:30 PM
I'm sure it's been asked but I have not found anything in the last few pages.

So...what grade, and what have you noticed about performance and economy?

Leo George Jr
11-06-10, 05:39 PM
I use 87 octane, runs like a champ. 22 city and 27 highway.

11-06-10, 05:54 PM
I use Shell, Chevron, Marathon 87 octane in my northstar STS. It runs like a champ with no problems. If the owners manual says it can use regular, then use regular. No use in wasting your money on premium. Why give the oil companies more money than they deserve.

11-06-10, 06:41 PM
I use nothing but Premium in my DTS Performance Sedan.
I bought it new and now have 92,000 miles on it.

I have checked it several times over the years with regular.
Invariably, I take about a 10% mileage hit and a very noticeably performance drop.

Since Premium is "RECOMMENDED" for my car and is only about 10% higher...I break even money wise and my car runs a lot better.

The extra Performance is an added bonus and doesn't cost me anything. :)

Texas Jim

11-06-10, 07:17 PM
I use mostly Shell premium in all my cars and motorcycles. I do this not because of any performance or mileage issues, but because of the Top Tier rating for Shell fuel. I will also use other Top Tier brands - premium when they have it. My wife (2008 DTS) probably does not adhere to this way of thinking, but she buys a lot of her own gasoline and has never complained (I think she buys mostly 89 octane of whatever is handy because it is cheap).

11-06-10, 07:18 PM
I have been running 87 octane (regular) in my Performance.Tried high test and not much difference as I can tell.No pings and milage is about same.Now keep in mind that all states do NOT regulate and enforce octane, so you could end up with less then 87.

11-06-10, 08:01 PM
From my 2001 STS owners manual:

Use regular unleaded gasoline rated at 87 octane or higher. However, for best performance and for trailer towing, you may wish to use middle grade or premium unleaded gasoline.

It is recommended that the gasoline meet specifications which were developed by the American Automobile Manufacturers Association (AAMA) and endorsed by the Canadian Motor Vehicle Manufacturers Association for better vehicle performance and engine protection. Gasolines meeting the AAMA specification could provide improved driveability and emission control system performance compared to other gasolines.

Be sure the posted octane for regular is at least 87 (at least 91 for premium). If the octane is less than 87, you may get a heavy knocking noise when you drive. If it’s bad enough, it can damage your engine.

If you’re using fuel rated at the recommended octane or higher and you hear heavy knocking, your engine needs service. But don’t worry if you hear a little pinging noise when you’re accelerating or driving up a hill. That’s normal, and you don’t have to buy a higher octane fuel to get rid of pinging. It’s the heavy, constant knock that means you have a problem.

I suspect the same language is in the owners manual for the DTS. Downloadable here: http://www.gm.com/gmownercenter/gm/?campaignId=&vin=

11-07-10, 06:32 AM
I use Shell Bronze 87 octane in Canada. When in the US my preference is Chevron, but when that's not available then I'll use any Top Tier Gasoline. http://www.toptiergas.com/retailers.html

11-07-10, 08:22 AM
The language in my 2006 DTS manual says to use Premium...

Use premium unleaded gasoline with a posted octane rating of 91 or higher.
You may also use regular unleaded gasoline rated at 87 octane or higher, but your vehicle’s acceleration may be slightly reduced, and you may notice a slight audible knocking noise, commonly referred to as spark knock.

I don't want mine knocking...so I just use Premium, like the manual says to.

Texas Jim

11-07-10, 11:32 AM
Plus, paying for a luxury car and neutering its performance with lower octane fuel just seems... silly.

383 LT1 SS
11-08-10, 10:19 AM
I have a 2007 DTS Performance and in the area that I live in I use 91 octane however there is no ethanol. In all of the other grades of fuel they have up to 10% ethanol. I do get better mileage with out ethanol blended fuel.

383 LT1 SS

11-08-10, 07:15 PM
I ran my 06 DTS to the low fuel warning and put in 10 gal of 87 octane. Noticed the performance difference immediately. It still ran smooth, and never knocked, but I could not wait to up the octane to 89 so the umph could return!

11-08-10, 07:32 PM
Super / Premium :penguin2::penguin2::penguin2::penguin2:

11-08-10, 09:36 PM
Manual to my suprise says "premium".That's what I use!

11-10-10, 07:31 AM
2006 dts I have used 87 but after reading this thread Ill ck and see if my station puts ethanol in their tanks of 91. Last trip with 87, 28 mpg highway. Its the time of year they start to blend ethanol into their gasoline and Im sure my mileage will drop using ethanol. Next trip I will try 91 anyway. Mike

11-10-10, 09:51 PM
I only use Sunoco Ultra (93) It's the best IMHO. diggerdog

11-11-10, 05:18 PM
I use 87 most of the time, but run 91 in about 1 out of every 4 tanks. I have not noticed any mileage difference or any pings.

11-16-10, 11:36 AM
I've been switching around between 87, 91 and 93, but mostly use Shell. Honestly, I can't tell the difference so far. I prefer to use Top Tier gas and Shell is the only ones near me that have that designation. Nonetheless, given some of the posts here, I think I'll take a look at my manual and see what it says for 2009. I may start opting for 93 exclusively.