Can I Use 87 Or Do I Have To Use Premium Fuel In My 99 Seville STS ? -NEW DRIVER PLEASE HELP !

CadillacLivin
0

Asked by CadillacLivin Apr 14, 2013 at 03:11 PM about the 1999 Cadillac Seville STS

Question type: General

5 Answers

tenspeed
53,645

You can use 87. The knock sensor will retard the ignition if it's not good enough and you will have less power and worse MPG's. Run two or three tank fulls, write down the gallons and mileage to determine your MPG's. Run two or three tanks of the next grade up and do the same. If you are getting better MPG's, use the higher grade gas. It costs less per mile and it's better for your engine. Keep track of your numbers at www.fuelly.com

2 out of 2 people think this is helpful.
CadillacLivin
0

Okay , Thank You Soo Much ! :) Appreciate It .

carpetguy53
185

the car will tell you right on the dash board to use premium if it does then that's what you use

1 out of 1 people think this is helpful.
Best Answer
bobkat
3,475

tenspeed is correct. Most any GM car will run on 87 Octane. It should be less power and mileage - but depending how you drive, you may not notice it. IF you get pinging or knocking on acceleration - then move up to the next Octane level. Sticking with a good brand of gas is important. Try to avoid the 'no-name' stations whenever possible. Their prices are usually lower because their gas is 'older' or has less cleaning additives.

soeville
0

I bought a 99 sts with 200 k then found this 4.6 has over 10:1 compression. DO NOT run anything less than premium! Dont rely on knock sensors. The reason these engines crap out head gaskets is people try running regular 87. When u hear a ping or knock, what is actually happening is an uncontrolled combustion process. This results in way higher cylinder pressures which strip the head bolts (which are too small to tolerate it) out of the block! Hence your head gasket didnt fail, your bolts did! Ive put 50 k on my caddy in 6 months. It see's routine w.o.t.up the b.c. mountains and its performed way past the so called "head gasket" expiry date with out issue!

Your Answer

Add photo

Related Questions

Seville
Looking for a Used Seville in your area?
CarGurus has 675 nationwide Seville listings starting at $1,977.
ZIP:

Search Cadillac Seville Questions

Cadillac Seville Experts

#1 Tom Demyan
Tom Demyan
Reputation 220
#2 carpetguy53
carpetguy53
Reputation 160
#3 tenspeed
tenspeed
Reputation 150
View All

Related Models For Sale

Used Cadillac DeVille"
61 Great Deals out of 3,171 listings starting at $1,698
Used Cadillac Eldorado"
475 listings starting at $2,695
Used Chevrolet Monte Carlo"
81 Great Deals out of 2,581 listings starting at $1,595
Used Chevrolet Impala"
1,751 Great Deals out of 60,230 listings starting at $990
Used BMW 7 Series"
138 Great Deals out of 5,393 listings starting at $2,300
Used Lincoln Town Car"
104 Great Deals out of 3,040 listings starting at $1,469
Used Chevrolet Camaro"
573 Great Deals out of 28,717 listings starting at $1,795
Used Cadillac Escalade"
226 Great Deals out of 6,914 listings starting at $3,999
Used Chevrolet Corvette"
319 Great Deals out of 11,219 listings starting at $3,900
Used Lincoln Continental"
5 Great Deals out of 495 listings starting at $1,000
Used Ford Mustang"
1,071 Great Deals out of 26,203 listings starting at $1,329

Used Cars For Sale

2003 Cadillac Seville STS For Sale
5 Great Deals out of 43 listings starting at $1,995