2004-2007 Cadillac CTS-V General Discussion Discussion, Chevron 93 vs Shell V Power in Cadillac CTS-V Series Forum - 2004 - 2007; Umm is it Shell that has V Power?
Well whatever the Yellow gas station, vs. Blue and White Chevron.
It all comes from the same refineries. Even the independant gas stations. The major brands just add their own "markers" (dyes & additives) to make sure that the dealers are buying from their own brand and for environmental tracing later on.
= All the same S**t.
I understand you low class fellows cannot afford the 94 ULTRA that Sunoco has to offer. I feel for you . I usually use BP 93 (ultimate) or Shell 93 (V Power) and I also feel a little more when I fill up with the V Power. Maybe its just me going Vvvvvvvv. The whole time the man is filling my tank. I feel so special.
Every once in a while, if you can, go to a Sunoco station that has 100oct unleaded. Put in a few gallons and run her hard. The fuel burns so clean that your exhaust pipes will have white residue on them instead of the black....really.
The race gas should do wonders for keeping your system clean, too. I've made a resolution to run a bottle of Techron through every 5 tanks, although I should just split the bottle into little shot bottles and use one every fill-up. Call me crazy but I'm really starting to have an affinity for this car...
IMO if the octane rating is accurate and the gas is "clean", you shouldn't be able to tell the difference between one 93 octane vs. another. And frankly, unless you can change the timing maps, you shouldn't really be able to tell the difference between 93 and 100 octane avgas or race gas.
Higher octane gasoline burns slower; this enables you to advance the timing more, allowing a more complete burn of your combustion charge and therefore a bigger bang by the time the piston passes TDC, thus a bigger downward push and more power. Engine "knock" is when the charge burns too fast and the combustion charge is fully ignited too early, literally driving the piston against the expanding gases (engines don't like that).
But, without an advance in timing to take advantage of the slower combustion of the higher octane, there is little advantage I think.
OK mechanical engineers, feel free to assault that analysis.
Won't the computer advance the timing for optimum performance when your at WOT? Jus as it Retards the timing if detonation is occuring.
If so, then a higher octane would allow more timing and more power! Am I right?
Automobile(s): 1985 Cadillac Sedan DeVille (83k miles)
Re: Chevron 93 vs Shell V Power
I'll give you my two cents. I have a 1989 Cadillac Sedan DeVille that was designed to run on 87 octane as well as a 1997.5 Ford Crown Victoria Limited that was designed to run on 87 octane. My Cadillac just hit 95k miles while the Ford passed 100k miles over two years ago. The Cadillac still runs fine on 87 octane. On the other hand, the Ford started to ping under hard acceleration on the freeways about three years ago and around 85k miles. I have typically used brand name gasoline over the years unless I'm on a road trip and cannot find "good" gas. I also throw in a can of B-12 once a year in each vehicle, so I knew that my injectors were clean...
I talked to my service advisor at the local Ford Lincoln Mercury dealership, and he told me to go to 93 octane. Not only did he say 93 octane, but to use Shell/Texaco 93 octane. He informed me that the 4.6 V8, while an outstanding motor, pings after you put a lot of miles on the car. Now this was before the Texaco stations became Shell stations as well as being before the start of "V-Power". He told me to drive my tank until it was nearly empty, and then fill the car up with Shell 93 octane. The difference was night and day. There was no longer any pinging under any circumstances in the Ford. On the other hand, when I took the car on a road trip the next time, I used Chevron 93 octane while on the road. I know Chevron is a good gasoline because that's what I still use in the Cadillac. The car took about 3/4 of a tank of Chevron 93 octane as I recall, and the pinging was back almost immediately. So, on the way home I tried to drive as far as possible until finding a Shell station, and I filled up with Shell 93 octane. I was ping free once again and have been ever since!
So, to make a long story short though I did want to provide enough details, I recommend Shell for 93 octane. But concerning 87 octane as I have tried Shell 87 octane in the Cadillac, the Shell makes the Cadillac's fuel economy drop a good 3-5% if not more. Therefore, I use Shell 93 in the Ford and Chevron 87 in the Cadillac. THE END
With them Ferds, I also find they start pinging once you get some miles on those 4.6s. Every Town Car I've driven(maybe 30) has done it. 1, maybe 2 tanks of 89 octane makes the pings go away for a month or 2.