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Differences between SLS and STS


mdesmond

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I am looking hard at getting a Seville, but I am having some trouble deciding which one to buy. There seem to be a large number of SLS's out there but only a couple STS's. I see that the STS was rated at 300hp but the SLS was rated at 275. I was wondering what the differences are between the 2 cars. I know the STS has a stiffer ride than the SLS (which is of no concern). I cannot imagine there are internal differences between the 2 motors. Would someone be able to tell me what the differences are and if I would be able to get the 25hp if I went with an SLS. Any help would be of help. Thanks in advance.

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A range of years you are looking at would help. The HP difference is due to cam timing. The final gear ratio is different giving the SLS an improvement in MPG on the interstate at the cost of quickness.

A few cosmetic differences that you have probably noted.

Your choice, but mine would be a 2000 or later. There were several engine improvements in 2000.

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

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The SLS is for "Sport Luxury Sedan" and the STS is for "Sport Touring Sedan." The STS package includes different engine tuning, different suspension tuning, and different transmission ratios and tuning, as noted by JimD. Engine differences are more than the cams, and include the compression ratio and possibly the fuel injection and exhaust manifolds. Other differences in appointments vary by year.

If you have an emphasis on performance, get the STS.

The STS package is available in the ETC, but not the Eldorado. Most people want the 4 doors and the Eldorado and ETC aren't out there in large numbers, but I got an ETC in 1997 because it was lighter and quicker than the STS that year.

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The first "S" in SLS and STS actually stands for Seville.

There are NO mechanical differences in the two engines beyond the camshafts. In fact, the only real difference is the lift and duration of the intake camshaft, and the programming in the PCM to compensate for that. The compression ratios are exactly the same. 10.3:1 for 93-99 engines, and 10.0:1 for 00-current FWD engines. Fuel injection and exhaust systems are exactly the same between the two cars.

The engines are more appropriately referred to as the LD8 (275 hp) and L37 (300 hp) engines. The LD8 generates 275 hp at 5600 rpm and 300 lb*ft of torque at 4000 rpm. The L37 generates 300 hp at 6000 rpm and 295 lb*ft at 4400 rpm. This makes a difference depending on how you plan to drive the car. Below about 5000 rpm, the LD8 engine actually makes more power and torque than the L37 engine. Only when you run the engines up to redline does the L37 have the advantage.

The transmission was exclusive to the engine. The LD8 engines got a 4T80-E transmission with a 3.11:1 final drive. The L37 engines got the same transmission, with the same forward and reverse gear ratios, but with a 3.71:1 final drive, to help alleviate the L37's softer low-end response.

Other differences include slight interior changes and bodywork changes. On the Seville, the SLS has minimal plastic body cladding on the sides and rear. The STS has plastic cladding on the lower half of all exterior panels. The STS sits slightly lower to the ground than an SLS, and will ride a little harsher.

All SLS models (through '97 anyway) came with S-rated tires, and a speed limiter of 112 mph. In general, the STS cars (save for the earlier ones) came standard with H-rated tires, and a speed limiter of 130 mph. Earlier STS cars came standard with (and later STS models had this as an option) Z-rated tires which completely removed the speed limiter.

To answer your question about getting the extra 25 hp in an SLS, it really can't be done. You could, in concept, swap the cams, but you'd be losing torque and low-end power that way, and with the SLS's relatively tall 3.11:1 final drive, you'd be losing performance, not gaining it. The actual field performance between the two is really too close to call. Production tolerances and previous maintenance can more than make up for a technical advantage based on HP or weight.

I have a chart on my website (linked below) which shows measured acceleration times for various FWD Cadillacs. These were taken from magazine publications. The point here isn't to argue whether one magazine is competent and another isn't, but to point out that you really can't say that a car from one year or body style is faster than another.

On that chart, someone had a '95 SLS that out-ran a lot of STSes. It just depends on the particular car. The difference in weight between an Eldorado and a Seville is not enough to definitively conclude one as faster or slower. It's too close to call in that regard.

http://www.jnjhome.net/cadillac/images/caddyperf.gif

Jason(2001 STS, White Diamond)

"When you turn your car on...does it return the favor?"

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Go for an STS 2000 or newer. After having an SLS I would much rather have the finer dressings of the STS with the wood steeringwheel and the painted trim at the bottom. With 2000 alot of upgrades as stated above but you use regular gas.. OH, and the Bose I merely forgot thats the reason why I wanted the 98 Seville over my 96 Deville. You cant beat the Bose sound system .I have had 5 Cadillacs and this was the first with Bose and I would really only consider having one with a Bose. STS in 98 and newer BOse was standard and only optional on the SLS package.

Michael -

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I would much rather have the finer dressings of the STS with the wood steeringwheel

The wood steering wheel & shift knob were optional on the SLS. At least they where on the '02, my SLS has it.

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And depending on the year considered, the wood steering wheel/shift knob weren't available at all (like, pre-98). After '98, the two cars started getting VERY similar in terms of options (like the wood interiors and StabiliTrak). Previous to '98, there were some real personality differences. The SLS was the more "traditional" Cadillac, with chrome grille, stand-up hood ornament, etc. The STS was the more "European" or sporty Cadillac, with monochromatic treatment, fog lights, body cladding, etc.

Don't get caught up in the differences in the engines -- that's the least of the differences really. What you'll notice more on a day-to-day basis are the "personality" differences mentioned above, depending on what model year range you're looking, Mdesmond.

Jason(2001 STS, White Diamond)

"When you turn your car on...does it return the favor?"

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my 1996 sts came factory with z rated tires, and yes the bose system rules, especially when you but some bass behind them. i have 2 alpine type r 12's witch give a nice thump. also the one guy at the local race shop (cam at cws tunning) put a northstar into a late 80's volks wagon, its crazyyyy.

my 1996 sts came factory with z rated tires, and yes the bose system rules, especially when you but some bass behind them. i have 2 alpine type r 12's witch give a nice thump. also the one guy at the local race shop (cam at cws tunning) put a northstar into a late 80's volks wagon, its crazyyyy.

my 1996 sts came factory with z rated tires, and yes the bose system rules, especially when you but some bass behind them. i have 2 alpine type r 12's witch give a nice thump. also the one guy at the local race shop (cam at cws tunning) put a northstar into a late 80's volks wagon, its crazyyyy.

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my 1996 sts came factory with z rated tires, and yes the bose system rules, especially when you but some bass behind them. i have 2 alpine type r 12's witch give a nice thump. also the one guy at the local race shop (cam at cws tunning) put a northstar into a late 80's volks wagon, its crazyyyy.

my 1996 sts came factory with z rated tires, and yes the bose system rules, especially when you but some bass behind them. i have 2 alpine type r 12's witch give a nice thump. also the one guy at the local race shop (cam at cws tunning) put a northstar into a late 80's volks wagon, its crazyyyy.

my 1996 sts came factory with z rated tires, and yes the bose system rules, especially when you but some bass behind them. i have 2 alpine type r 12's witch give a nice thump. also the one guy at the local race shop (cam at cws tunning) put a northstar into a late 80's volks wagon, its crazyyyy.

I think I got it the first time...Thanks. :lol::lol:

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I have seen very few SLS before 02 with the wood steering wheel The steering wheel was changed to yours in 01 and thats when the SLS package really was like an STS wood steering wheels and the painted bottom trim.

michael-

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And don't forget about CVRSS (Continuously Variable Road Sensing Suspension). Once again, depending on year, STS's had it, SLS's did not. This was the electronic controlled valving in the shocks, my '99 has it in theory. In actual practice, I can't tell the difference...of course, never having driven an SLS, how would I know. The last model STS's, 2003 (MAYBE 2004, but they're like ghosts) had the MagnaRide shocks....not that you'll find a dealership that knows anything about that.

Don't let the lower fuel mileage part of the replies concern you too much, I just averaged 26.9 MPG coming back across rt 70 from Pittsburgh to Columbus, flat ground, but NOT TOO SHABBY. This is a '99 STS using regular gas (which does not effect driveability in any way). It'll do 1 - 1.5 mpg better on premium.

Never underestimate the amount of a persons greed.

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My 2003 STS has the MagneRide. Let me tell you, it's absolutely awesome. It's soooo good that it's offered in the Corvette. It's also offered in the latest Ferrari.

Yup, you heard it right, GM technology is in a Ferrari, the 599 GTP Fiorano!

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

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And don't forget about CVRSS (Continuously Variable Road Sensing Suspension). Once again, depending on year, STS's had it, SLS's did not. This was the electronic controlled valving in the shocks, my '99 has it in theory. In actual practice, I can't tell the difference...of course, never having driven an SLS, how would I know.

In 1996, the STS had CV-RSS as standard, and it wasn't even available on the SLS. Beginning in 1997, it was standard on both models.

Jason(2001 STS, White Diamond)

"When you turn your car on...does it return the favor?"

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When I bought mine it was the subdued look and the handling as to why i chose a STS. In as far as "get-up-and go" they're pretty close to one another. To me it seems the STS breathes much better than the SLS, but the SLS has very good throttle response at lower RPM's.

If fuel economy is a concern, then the SLS is the way to go.

Jim

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