I'm pumped...I just bought a 1991 Sedan DeVille that's in mint condition. I did a lot of research before I purchased the vehicle and I came across the Cadillac Forum - the info that I got from the forum influenced my decision to "pull the trigger" and actually buy the car - so "Thank You" forum members.

My new baby has 65,000 miles - my goal is to get at least 150,000 miles out of it. I heard that Mobil 1 Synthentic Oil will help to increase the life of the engine - is this good oil for this car ?

I read in the manual to use at least 91 octane GASOLINE - is this accurate ?

If there's any other advice for a NCO (NewCadiOwner) please feel free to share.


Thanks Again,

Stonehill

:welcome:

65K, that's not even broke-in for a 4.9!! ;)

I found that if I don't use the recommended premium fuel the engine knocks, as there is no knock sensor that retards the timing in these older cars. You might get away with mid-grade but I might be concerned about detonation. I've read here that in hot summer use premium, in colder weather you might get away with mid-grade. Depending on where you live ......

There are probably dozens of threads on synthetic oil so try a search here and see what you find. I ran Mobil one one winter and didn't notice anything different, but I like the idea it supposedly remains "fluid" even at -45 for "start-up" protection, etc.

You should easily get 150K out of it and smile all the way.

Welcome Stonehill!

Congrats on your recent purchase! Good luck. Thanks for joining the forum.
We are glad you have found the information here useful.
Here are a couple more links:
http://100megsfree4.com/cadillac/cad1990/cad91.htm
http://100megsfree4.com/cadillac/cad1990/cad91d.htm
On-board diagnostics:
http://myweb.accessus.net/~090/resources-cad.html#main
:welcome:
Paul

:welcome: to the forum. Congrats on your DeVille. I wish you the best of luck with it.

hey buddy. congrats on the purchase :)

Welcome to the forums.

Thanks for welcoming me to the forum and all of the advice.

Congrats on your new car and welcome to the forums!
As you found out, this place is great.
See you around the forums!