Does anyone buy medium grade gasoline?

[Vette73]

Isn't 91 recommended for your CTS?

Nope. The CTS-V calls for prem (91-93) but the V6 runs all 250+ hp on 87.

 

[LTC8K6]

Nope. The CTS-V calls for prem (91-93) but the V6 runs all 250+ hp on 87.

This is purportedly from the 2004 CTS owner's manual:

Gasoline Octane
Use premium unleaded gasoline with a posted octane of
91 or higher for best performance. You may also use
middle grade or regular unleaded gasoline rated at
87 octane or higher, but your vehicle’s acceleration may
be slightly reduced. If the octane is less than 87, you
may get a heavy knocking noise when you drive. If this
occurs, use a gasoline rated at 87 octane or higher
as soon as possible. Otherwise, you might damage
your engine.

 

[JCH13]

I'd like to know what the people that say they use 93 are actually driving.

I use 93 on my MS3, where the boost has been freed up to about 16.2psi. It runs okay on 91 though. I also use it in my Miata, which only hits about 10psi these days, but will be getting an EBC and going to 14psi.

 

[punjabiplaya]

Mazdaspeed3. 91 or above.

 

[Vette73]

This is purportedly from the 2004 CTS owner's manual:

Gasoline Octane
Use premium unleaded gasoline with a posted octane of
91 or higher for best performance. You may also use
middle grade or regular unleaded gasoline rated at
87 octane or higher, but your vehicle’s acceleration may
be slightly reduced. If the octane is less than 87, you
may get a heavy knocking noise when you drive. If this
occurs, use a gasoline rated at 87 octane or higher
as soon as possible. Otherwise, you might damage
your engine.

Thats the CTS-V.
Most owners report the same as me.
"Last month the 3.6L CTS I picked up states in the manual that it is designed to run on 87 octane."

Even the new DI 300+hp 3.6 calls for 87.
"It makes 302hp on 87 octane all the others need premium to reach the kind of ..."


http://www.theautochannel.com/news/2005/06/15/126716.html
2005 Cadillac CTS 3.6 Review
Fuel Requirement 87 octane unleaded regular gasoline

 

[CraigRT]

Saturns get anything regular.
Nissan was fed Shell or Sunoco premium.

 

[LTC8K6]

Thats the CTS-V.
Most owners report the same as me.
"Last month the 3.6L CTS I picked up states in the manual that it is designed to run on 87 octane."

Even the new DI 300+hp 3.6 calls for 87.
"It makes 302hp on 87 octane all the others need premium to reach the kind of ..."


http://www.theautochannel.com/news/2005/06/15/126716.html
2005 Cadillac CTS 3.6 Review
Fuel Requirement 87 octane unleaded regular gasoline

Okay, just found where I got that quote from. Check it out and tell me what you think. No mention of a V8 in the manual, just a 3.2 and 3.6 V6, so what's going on?

http://www.mediafire.com/?gcqg1cwox68yrng

 

[LTC8K6]

Weird. EPA FE site shows the 3.2L taking premium and the 3.6L taking regular...

 

[exdeath]

I'd like to know what the people that say they use 93 are actually driving.

4.6L @ 17 psi boost and 19-21 degrees timing WOT and putting down 624 HP at the tire. To make matters worse a twin screw builds boost instantly at any rpm, and sees peak boost by 2500 rpm when the engine is at its peak load at wot.

If I were to get non premium or lower octane fuel in the tank it would be siphoned out and the car lapped around the block without boost until it ran out of gas, then filled with premium.

 

[Vette73]

^^

Yea the 3.2L is the first year motor (2003). It is an updated Saab motor but had issues. One reason I tell anybody looking at CTS to not touch the 2003/3.2. Let alone requiring prem fuel for not much power.

The 3.6 and 2.8 are the same basic motor. The 3.2 is based off the 2.5/3.0 that was used in Saabs and Saturn L300's. Even after the minor update it still has major timing belt issues.

 

[LTC8K6]

^^

Yea the 3.2L is the first year motor (2003). It is an updated Saab motor but had issues. One reason I tell anybody looking at CTS to not touch the 2003/3.2. Let alone requiring prem fuel for not much power.

The 3.6 and 2.8 are the same basic motor. The 3.2 is based off the 2.5/3.0 that was used in Saabs and Saturn L300's. Even after the minor update it still has major timing belt issues.

Yeah but the 2004 manual makes no distinction between the 3.2 and 3.6 as far as fuel. Just says to use premium. Wonder why?

 

[Vetterin]

Duh, well obviously, it's more expensive therefore it MUST be better for my engine.

That's exactly what my neighbor says as 91 is the ONLY gas she has ever put in her ESCORT. But then again I doubt that she drives 3000 miles a year so she really isn't spending that much.

 

[Vic Vega]

I'd like to know what the people that say they use 93 are actually driving.

High compression DOHC V8... 87 pings like all get out.

 

[Vette73]

Yeah but the 2004 manual makes no distinction between the 3.2 and 3.6 as far as fuel. Just says to use premium. Wonder why?

No 3.2L in 2004. There may be some 04 MODELs that were made in 03 that had the 3.2, but no 04 3.2's. I think it was ranked like 99% 3.6 and 1% 3.2.
But even then the 3.2L model should have the Prem gas in the manual.

 

[QuantumPion]

I'd like to know what the people that say they use 93 are actually driving.

I have a Civic SI which requires 91 to prevent knocking. I have not tried using a lower octane to see at what point it would knock though.

 

[EightySix Four]

4.6L @ 17 psi boost and 19-21 degrees timing WOT and putting down 624 HP at the tire. To make matters worse a twin screw builds boost instantly at any rpm, and sees peak boost by 2500 rpm when the engine is at its peak load at wot.

If I were to get non premium or lower octane fuel in the tank it would be siphoned out and the car lapped around the block without boost until it ran out of gas, then filled with premium.

Same, lower displacement and fewer cylinders but more boost 😛 I had to detune it when I was driving from Dallas to Vegas because of how crappy the gas was on the way.

Isn't 89 just a blend of the 87 and 93 at the pump?

 

[Vette73]

Same, lower displacement and fewer cylinders but more boost 😛 I had to detune it when I was driving from Dallas to Vegas because of how crappy the gas was on the way.

Isn't 89 just a blend of the 87 and 93 at the pump?

Most places I have seen yes. I thought it use to be pre-mixed a long time ago but not sure of that.
When people ask that I tell them to count how many tanks a station has. 😉

 

[CVSiN]

forced to use premium on my G35 Coupe..

would use 89 if I could get away with it.

 

[PricklyPete]

93 in both of our cars.

 

[WhoBeDaPlaya]

93 in my 06 Lincoln LS (91+) with its 10.8 comp ratio.

 

[Dr. Detroit]

I'd like to know what the people that say they use 93 are actually driving.

91- is the best you can do in California.

My last two cars required Premium due to either the high Compression Ratio or the factory Turbo.

 

[jlee]

I'd like to know what the people that say they use 93 are actually driving.

1991 Toyota MR2 Turbo with CT20B turbo at 16psi, going to TD05 20G and more fuel
2004 Subaru Forester XT with STi turbo/TMIC and 3" turboback exhaust

 

[Excelsior]

I'd like to know what the people that say they use 93 are actually driving.

A Passat 1.8T with ecu flash for 93 octane.

 

[charrison]

I'd like to know what the people that say they use 93 are actually driving.

2000 nissan maxima. Starting pinging after about 60k miles if it did not get premium.

 

[LTC8K6]

No 3.2L in 2004. There may be some 04 MODELs that were made in 03 that had the 3.2, but no 04 3.2's. I think it was ranked like 99% 3.6 and 1% 3.2.
But even then the 3.2L model should have the Prem gas in the manual.

The replacement of the 3.2 with the 3.6 in 2004 probably explains the owner's manual discrepancy. The manuals probably had to be changed hastily to add the 3.6, and they didn't bother to change the octane recommendation page, or they just missed it.