what type of fuel?

[RobertCTS]

Originally Posted by tonytun

o0 shit am i wasting my money then? :-( i use 93 on my car--- i have a 2.8 cts 2007 but i did notice dat when i was using 87 the gas wouldnt last long so i started using 93 and saw a difference and another thing remember guys i live in miami and is hot as hell here everyday. what do you guys think??? should i go back to 87? and if i do would dat affect my car bcuz i was using 93?

It's the placebo effect IMO. The CTS 2.8 & 3.6 were designed to run on 87 octane. Some gas station may get condensation in their gas tanks(water) and this can make your car run lousey!

[caddy1219]

I am in Phoenix so my the 87 does break down faster in the tank and has condensation, where as the 93 has a little more additives that stops condensation.

[cossie1msu]

The higher the compression ratio the more effect higher octane fuel will have. For example the new '08 direct injection cts. Also vehicles with turbos/superchargers will need higher octanes due to the greater amount of air passing into the engine. If not used it will place too much stress on the turbo and burn it out. I use premium(92-94) just because I can't sleep well thinking that I'm not getting what I paid for (hp) and all that crap that builds up on the valves over time. Just my thoughts

[tonytun]

Originally Posted by RobertCTS

It's the placebo effect IMO. The CTS 2.8 & 3.6 were designed to run on 87 octane. Some gas station may get condensation in their gas tanks(water) and this can make your car run lousey!

so......what should i use? or what should i do? lol

[caddy1219]

IMO I would say use Premium, that is my thoughts about it but it is up to you

[Paco.]

Why is higher octane more recommended for the 03 as opposed to newer models?

[RobertCTS]

Originally Posted by tonytun

so......what should i use? or what should i do? lol

Tony,
87 octane will work great for your '07. Any more is a waste of $$

[RobertCTS]

Originally Posted by Paco.

Why is higher octane more recommended for the 03 as opposed to newer models?

The '03 3.2 had a higher compression ratio requiring higher octane gas. The 3.6 and 2.8 are fine with 87 octane.

[tonytun]

ok thank you Robert

[RobertCTS]

Originally Posted by tonytun

ok thank you Robert

ZOOM Zoom Tony!!!

[Coma]

87 always.

[bigblockcadillac]

I use the highest octane they got, but I got an 03 w/ the 3.2. No choice!!!
What can I say, the bitch has expensive taste

[Paco.]

Originally Posted by bigblockcadillac

I use the highest octane they got, but I got an 03 w/ the 3.2. No choice!!!
What can I say, the bitch has expensive taste

LOL...so I should never use 87 with my '03? I've only been putting the highest, but I guess the medium 91 is fine?

[djnas]

hey guys...

i have the 03 CTS and from my intepretation of the manual it says u can use 87 Octane, but Preimum is obviously recommended, I have put on about 8000KMs on the car since ive had it, I live in Toronto and i have used 87 octane for the majority of my driving.. I have to say it works fine..

However on my last fillup i used 91 octane and the acceleration at lower speeds is certainly better and noticable,

also i noticed once when i started my car it vibrated a bit (it was near empty on 87 octane gas) and when i put premium i didnt notice it. It could just be a one time thing cuz i never noticed a slight vibration before, even when using87 octane fuel.

My take is that 87 octane is ok for the 03 CTS if u dont push ur CTS hard and are an average driver, but if u want better performance premium is definately the way to go...

any1 else here use 87 in thier 03 CTS? ive only driven 8000KMs so maybe thats why i didnt notice a difference yet, any1 else here have more experience with this?

[BlueMalibu]

I was using 89 Octane until recently. I was in a freeway traffic jam recently and had the radio off and could hear some slight knock when tipping into the throttle. This caused me to switch to premium and the knock has gone away. When the weather gets cooler I'll probably switch back.