High octane Northstar

[Art Woody]

I have a friend who just purchased a cream puff 99 deVille. The dealership told him to use only premium grade fuel in the Northstar engine. Being a fifties guy, I am not familiar with this high tech engine. I have gleaned from this forum that this may not be a Cadillac fans favorite, but he is not hurt by the price he paid for the amount of luxury he is enjoying, as long as his luck holds out on any future maintenance woes. Any comments on the premium fuel recommendation?

[Richard Sills - CLC #936]

Art, I suggest your friend check his owners manual and see what grade of fuel Cadillac recommended for that car.  I have driven a 96 deVille Concours with the 300 hp. Northstar engine for almost 9 years.  I recall being told to use premium fuel only, and I think there is a similar instruction inside the fuel door lid.  I have followed that recommendation, and the car still runs great.

[Rusty Shepherd CLC 6397]

The first-generation Northstar (through 99) required premium. His car will have Premium Unleaded Only on the gas gauge and on the fuel door.  Beginning with the 2000 models, it was not required, but still recommended. BTW: All FWD Cadillacs from 1990-1999, not just those with the Northstar engine, require premium.

[David #19063]

Hello Art,

Yes, he should ONLY run premium in it.  I have a 129k mile 300 HP Nortstar in my 96 Concours and never had an engine issue.

I know the 2000+ Northstars CAN run on lower grades, but I would recommend those also to only run on premium as well if one does not want any engine issues as the miles add up.

IMHO.

David

[Tim Coy #11513]

My 2001 Eldorado requires mid-grade fuel, so Ive never pumped regular into it. Fortunately, Costco sells premium at a price lower than most other stations charge for mid-grade, so I usually go there. I have no problems whatsover when it comes to performance.

[Art Woody]

Thanks for all the replies, great to know that one can count on this forum for answers on such a wide array of topics and models. I think the difference in the cost of premium fuel is nothing compared to $500-$600 a month payment one would pay on a new car of equal equipment & quality. Thanks again.

[Bill Burton #19057]

Ive used regular, midgrade and premium in my 97 Deville.  I can detect a difference in performance and mileage when I use lower grades.  Typically, I lose one or more miles per gallon and going up the hill on freeway I use occasionally, I feel a reduction in power.  The same throttle setting on cruise control will drop about three miles per hour lower.  The engine doesnt seem to have any problem with lower grades, but I do believe that you probably will get better overall performance with the higher grade.  The computer does an excellent job of adapting by reducing the performance level to compensate and prevent problems.  Happy New Year and best wishes.  Bill Burton

[Art Woody]

Any of you guys experience any leaks or oil consumption that Ive read about on this forum with your first generation Northstar? Just wondering.

[Rusty Shepherd CLC 6397]

I owned two first-generation Northstar cars, both bought new. Neither one leaked oil, but they both used oil right from the beginning. One used a quart about every 1600 miles, the other about every 1200; Cadillac only considered consumption greater than a quart every 1,000 miles a problem.  When I inquired, I got a letter back giving that policy and saying that all modern engines use oil which, of course, is not true.

[Greg McDonnell CLC# 20841]

Which years did the First Generation Northstar span? Are we now on the Second Generation or have we reached the Third Generation.  I have a 98 SLS and I havent noticed any oil consumption.  Of course, I drive mine minimally, but the oil level is where it should be (full) on the dipstick when I check it.

Greg

[Rusty Shepherd CLC 6397]

1993-1999 is generally considered first generation; there were many improvements made during those years, but the engines were still basically the original design.  The Northstar was really completely redone for the 2000 model year with very few parts carried over, so that year would be the beginning of the second generation. The engine was adapted for longitudinal/RWD application with the introduction of the SRX and STS and improvements were again made, so I guess you could call the current Northstar third generation. Yours is the first Northstar Ive ever heard of that didnt use oil. When my neighbor was going to buy a very low mileage 99 SDV several years ago, I told him to expect oil consumption greater than his 92. He asked the service manager if all the Northstar engines used oil and was told yes.  How much? "Around a quart every 1000-1200 miles".

[Greg McDonnell]

Thanks for the information!  

 I guess my SLSs Northstar probably would use oil (or at least it would be noticeable) if I drove it more.  As it is, the months exceed the mileage (3 months/3,000 miles) when I have the oil changed.  I usually let it go for about 5-6 months before changing it since I put so few miles on the car.  It will be 9 years old next month and it only has a 39K miles.  

[Bruce Reynolds # 18992]

Gday Greg,

The first time you take your car on a really long drive, say over 200 miles, (well, that is a long drive for me in Tasmania), then check the oil the next day, you might find that the level is low.

It is surprising just how much "low mileage" contaminent gets boiled away after such a drive.

Bruce,
The Tassie Devil(le),
60 CDV

[Greg McDonnell CLC#20841]

Hello Bruce,

Interestingly, I just had the oil changed in the SLS and took the car on a (roundtrip)200 mile jaunt at Christmas.  I went out and checked the dipstick a little while ago.  I had just moved the car to clean leaves out from under it and then moved it back into its parking place an hour or so ago so some oil may still not have drained back into the pan.  The oil was indeed down on the dipstick (a couple of notches from Max).  It had been at Max when it was changed just a few weeks ago.  

Thanks for the suggestion.  Guess my Northstar uses oil just like all the rest of them.  I just never noticed it.  I will check it more often now that this has been brought to my attention.  Glad this thread was started.  I would hate to let the oil get low in that engine.  I use the car so infrequently, I forget to check the oil as often as I should.  

Greg