Jump to content
CaddyInfo Cadillac Forum

SLS vs STS Horsepower ratings


Bill A

Recommended Posts

I'm moving from a 96 STS to a 99 SLS I bought with only 35k miles. Yes it was owned by a liitle old lady.

I suspect I may miss the extra 25 HP of the STS.

Does any forum member know what the HP diffence between the 275 HP & 300 HP Northstar is attributed too?

I might be interested in doing the mods if not hugely complicated.

Is there different chip or something easy and cost effective to do to get back some of the HP?

Bill A

Altoona, IA

Link to comment
Share on other sites


In a nutshell, the camshafts and I believe the bore of both are slightly different. Accordingly, the specs will be slightly different. The less horsepower version will produce more torque and generally will have more efficient fuel economy.

Link to comment
Share on other sites

Different intake cams. Different final drive ratio. Different PCM "tuning."

Regards,

Warren

EDIT: I forgot to wish you many happy miles. Consider it done. ;)

Regards,

Warren

Posted Image

There is no means of avoiding the final collapse of a boom brought about by credit expansion. The alternative is only whether the crisis should come sooner as the result of a voluntary abandonment of further credit expansion, or later as a final and total catastrophe of the currency system involved. - Ludwig von Mises

Link to comment
Share on other sites

Different intake cams. Different final drive ratio. Different PCM "tuning."

Regards,

Warren

Thanks Warren & Mac.

The cam issue is a mod I am not willing to deal with.

Do you know of an aftermarket chip that might boost the SLS performance?

Bill A

Link to comment
Share on other sites

In a nutshell, the camshafts and I believe the bore of both are slightly different. Accordingly, the specs will be slightly different. The less horsepower version will produce more torque and generally will have more efficient fuel economy.

Mac - Thanks for reply.

Nice Eldo!

Link to comment
Share on other sites

Perhaps the biggest thing you'll miss is the 3.71 STS final drive ratio. The SLS has 3.11s. However this 3.11s help the SLS achieve much better economy.

2003 Seville STS 43k miles with the Bose Sound, Navigation System, HID Headlamps, and MagneRide

1993 DeVille. Looks great inside and out! 298k miles!

IPB Image

Link to comment
Share on other sites

The cam issue is a mod I am not willing to deal with.

Do you know of an aftermarket chip that might boost the SLS performance?

Bill A

The cam issue is not one I believe any sane person would want to deal with. Ditto the final drive ratio. As for the PCM issues, . . . :P :P :P

Our gone-but-not-forgotten "Guru" pointed out that the engineering staff had pretty much picked all the "low hanging fruit" during the Northstar development process. I'd be concerned that any after market chip that offered to increase horsepower would likely exceed the "safety envelope" of the engine. It wouldn't go in my car!

Regards,

Warren

EDIT: Pretty much the only thing you can do is to get more air moving through the engine. Nothing much to do on the intake side; that leaves the exhaust side. I guess it depends on whether or not you want your Cadillac to sound like a Camaro?

Posted Image

There is no means of avoiding the final collapse of a boom brought about by credit expansion. The alternative is only whether the crisis should come sooner as the result of a voluntary abandonment of further credit expansion, or later as a final and total catastrophe of the currency system involved. - Ludwig von Mises

Link to comment
Share on other sites

The final gearing gives you an edge in fuel economy that you will give up quickly if you try to modify the engine tuning for performance. The VIN Y cars drive very much like the VIN 9 cars in nearly all driving, in my experience with loaners and other cars. The VIN 9 "800 lb gorilla" shows only above 4,000 RPM at WOT, with a noticeable passing surge from 50 mph to 80 mph in second gear, with corresponding power out in the license-eating speed range in third. That, and the 150 mph top end is achievable with the VIN 9 engine and is intended for the Autobahn, and there is a one-car-length surge at the top end of low gear.

The one thing that I would recommend is Borlas or equivalent stainless steel turbo mufflers. If you like the exhaust note, you will get a few percent increase in torque and gas mileage.

But, I think you will love your SLS as it is. Congratulations, and many happy miles.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

Link to comment
Share on other sites

you will hate the difference.

I had a 99 sts, went to a 97 deville.

no comparison...

deville is a dog compared to the 300 screaming horsepower of the sts.

no more torque steer...

no more crazy fast acceleration...

no more FUN!

good luck...

I gave my 97 deville to my daughter...

i am out to find another sts...2003...

have fun driving..

jim

Link to comment
Share on other sites

The other thing you'll notice is the softer suspension on the SLS. Acceleration from stop is pretty close.

- The STS has more grunt at highway speeds (70+ MPH) than the 275 HP flavor (IMO).

- I beleive the overall torque is pretty even on both engines (300 vs 295) but the 275 HP engine has it at lower RPM's.

- The STS versions usually come better equipped.

- The SLS give better fuel economy

When I was picking and choosing I prefered the sub-dued looks and the suspension of the STS over the SLS, otherwise it was a wash. 2004 SLS took the subdued front end from the STS's (weren't any STS's produced that year).

Jim

Link to comment
Share on other sites

Ditto on that. IIRC, you're not going to find the MagneRide suspension on the SLS. If you can get the MagneRide, get it!

2003 Seville STS 43k miles with the Bose Sound, Navigation System, HID Headlamps, and MagneRide

1993 DeVille. Looks great inside and out! 298k miles!

IPB Image

Link to comment
Share on other sites

I have a nice 96 STS for sale.

79,800 miles, 2 owner.

Details in the for sale forum or contact me if interested.

Good news is I still have a 2000 Trans AM WS6 for my hot rod fix.

Only about 650 miles to me in Des Moines from Columbus, OH. Not sure exactly where you are but I thought OH.

Bill A

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...