Just curious because the later ones can run on 87 and I'm guessing compression was lowered to make that possible. Surely not a big difference if any but is there any noticeable performance loss?

the weight on the 98+ is more a factor than anything else. 3/10ths of a point of compression is nearly nothing.

My 96 deville always felt quicker than my 02 base deville does. The 96 would crackle on 93 octane and could consistantly beat a friends 96 deville by a car lenght in a zero to 75 mpg dig.
I have not gone against him yet with the 02 yet but plan to when the opportunity presents itself. I will report the results when it happens.

simple answer
yes
very much so

Put premium in it when you do run him. That will prevent the knock sensor from retarding the timing should it pick up any spark knock.

I test drove a 2003 DHS with 60,000 miles on it. I was very happy to get back in my STS. That thing was SLOOOOOW compred to my STS. Not sure if it was the 300 Horsepower N*????

Must have been the gear ratio's and stuff....Or somthing. I didnt feel any of the power that my STS has in the DHS. I didnt like it at all.

EDIT: Yea almost forgot, Could have also been the weight+ gearing differences....

STS is 300 HP & 3.71 final drive.
DHS is 275 HP & 3.11 final drive.

Just curious because the later ones can run on 87 and I'm guessing compression was lowered to make that possible. Surely not a big difference if any but is there any noticeable performance loss?
Yes the engine produces less power, but the same Peak Power

the weight on the 98+ is more a factor than anything else. 3/10ths of a point of compression is nearly nothing.
Correct it has NOTHING to do with .3 less compression
You pull that much timing out of the program you can run regular

My 96 deville always felt quicker than my 02 base deville does. The 96 would crackle on 93 octane and could consistantly beat a friends 96 deville by a car lenght in a zero to 75 mpg dig.
I have not gone against him yet with the 02 yet but plan to when the opportunity presents itself. I will report the results when it happens.

Correct agian, But the 02 is very very unlikey to have a Head Gasket Failure. The revise engine has a ton of advances to it.

Put premium in it when you do run him. That will prevent the knock sensor from retarding the timing should it pick up any spark knock.

This engine was designed for Premium. I feel it should run on Premium, and the so does the General, but it is not required.

Myth!!!!! Octane 99 and prior VS 00+ (http://www.cadillacforums.com/forums/northstar-performance-technical-discussion/114439-myth-octane-99-prior-vs-00-a.html)

I test drove a 2003 DHS with 60,000 miles on it. I was very happy to get back in my STS. That thing was SLOOOOOW compred to my STS. Not sure if it was the 300 Horsepower N*????

Must have been the gear ratio's and stuff....Or somthing. I didnt feel any of the power that my STS has in the DHS. I didnt like it at all.

EDIT: Yea almost forgot, Could have also been the weight+ gearing differences....

Gears and a Tune for the Gears less than $1000 and then you have a very nice ride.
I could even load a stock DTS with no mods in it. So a 60K DHS or SLS looks good at the lower price than a DTS or STS

STS is 300 HP & 3.71 final drive.
DHS is 275 HP & 3.11 final drive.

I can fix that

well i have a 2000 ETC and a 2001 DTS.
and the ETC is way quicker and has alot better acceleration because of i guess the weight. when i got the DTS i was kinda sad it didn't feel as power full.
my 94 ETC would also probably be quicker then the DTS