2004 N* fuel choices...premium wins
Cadillac
 

Cadillac Forums | Help Us Help You | Advertise | Cadillac Parts | Cadillac News | Cadillac Classifieds / (Old System)

Cadillac Technical Archive | Cadillac Dealers | Cadillac Reviews | Cadillac Dealer Reviews | Cadillac Vendors

CadillacForums.com is the premier Cadillac Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Page 1 of 3 1 2 3 LastLast
Results 1 to 15 of 38
Like Tree6Likes
Cadillac DeVille 1985 to 2005 including:
1985-1992 Fleetwood, 1993 Sixty Special, All FWD Forum Discussion, 2004 N* fuel choices...premium wins in Past Cadillac Vehicle Discussion; I had been running my 04 DHS on 87 octane without problem but after carefully reading the wording of the ...
  1. #1
    knotgoalie's Avatar
    knotgoalie is offline Cadillac Owners Fanatic
    Automobile(s): 04 DHS, 99 F150 4x4 SCAB
    Join Date
    Oct 2013
    Location
    Ontario, Canada
    Age
    58
    Posts
    272

    2004 N* fuel choices...premium wins

    I had been running my 04 DHS on 87 octane without problem but after carefully reading the wording of the OM, I switched to premium. Yes, the computer will retard the timing and make all of the adjustments to use regular gas but boy did my car wake up with the use of premium gas.

    I can't be too surprised that a 10:1 engine would perform more efficiently on a higher octane fuel than it would on 87 but what surprised me was how much better it performed. On 87 I had done a couple of WOT to pass another car and quite frankly was not impressed with the results although I would rate the passing efforts as "adequate" overall. Moving to higher octane gas opened for me, a whole different perspective of the N*. I tried it today on the hwy between towns (6mi, no traffic to hit) and a stomp from 80kph had me up to 140kph in a few short seconds with noticeable push back into the seat and a beautiful, previously unheard song from under the hood.

    For the difference of a very few $ per tank offset by a + in the fuel economy, I'm sticking with the good stuff, not the "bar stock" for my Cad.

    Opinions please ???


    J.R.

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    basscatt's Avatar
    basscatt is online now Cadillac Owners 10000+ Posts
    Automobile(s): 89 Coupe DeVille, 95 Sedan DeVille, 03 SLS, two 02 DHS's
    Join Date
    Feb 2004
    Location
    Minnesota
    Age
    63
    Posts
    10,052

    Re: 2004 N* fuel choices...premium wins

    Quote Originally Posted by knotgoalie View Post
    I had been running my 04 DHS on 87 octane without problem but after carefully reading the wording of the OM, I switched to premium. Yes, the computer will retard the timing and make all of the adjustments to use regular gas but boy did my car wake up with the use of premium gas.

    I can't be too surprised that a 10:1 engine would perform more efficiently on a higher octane fuel than it would on 87 but what surprised me was how much better it performed. On 87 I had done a couple of WOT to pass another car and quite frankly was not impressed with the results although I would rate the passing efforts as "adequate" overall. Moving to higher octane gas opened for me, a whole different perspective of the N*. I tried it today on the hwy between towns (6mi, no traffic to hit) and a stomp from 80kph had me up to 140kph in a few short seconds with noticeable push back into the seat and a beautiful, previously unheard song from under the hood.

    For the difference of a very few $ per tank offset by a + in the fuel economy, I'm sticking with the good stuff, not the "bar stock" for my Cad.

    Opinions please ???


    J.R.
    ---------------------------
    unless you are towing - or racing -
    you are wasting money buying anything higher 87 gas -

    you won't get any more power - or better gas mileage -

    as far as the "BUTT-DYNO" test goes - it proves nothing -

    but if it makes YOU feel better - go for it -
    the gas companies appreciate the extra money -

  4. #3
    MoistCabbage's Avatar
    MoistCabbage is offline Cadillac Owners 10000+ Posts
    Automobile(s): Crimson 2001 Seville STS, 1990 Seville (RIP)
    Join Date
    Sep 2010
    Location
    East Boston MA.
    Age
    26
    Posts
    21,898
    Yeah, the premium fuel isn't going to make a noticeable difference, and definitely no difference in engine note. Any difference in fuel economy would be extremely minuscule.

  5. #4
    knotgoalie's Avatar
    knotgoalie is offline Cadillac Owners Fanatic
    Automobile(s): 04 DHS, 99 F150 4x4 SCAB
    Join Date
    Oct 2013
    Location
    Ontario, Canada
    Age
    58
    Posts
    272

    Re: 2004 N* fuel choices...premium wins

    I've only just started with this guys so some more shall we say, "scientific" results will come down the road. It idles somewhat smoother and pulls noticeably better when kicked running premium. I'll try it for a while to see what the real differences are since it only adds about $6~$7 per tank for the premium so no biggie. If it actually turns out that the car prefers the higher octane, then it gets it but if there is no long term appreciable gain perceived, it goes back to 87 octane.


    J.R.

  6. #5
    LoveMyLac is offline Cadillac Owners Member
    Automobile(s): 1999 DeVille D'Elegence (RIP) 2001 Cadillac DeVille DTS
    Join Date
    Oct 2013
    Posts
    82

    Re: 2004 N* fuel choices...premium wins

    I have put 91 in my 01 DTS out of habit from filling up my 99 Deville and didn't notice anything.

  7. #6
    SUPER LAC DEVILLE's Avatar
    SUPER LAC DEVILLE is offline Cadillac Owners Enthusiast
    Automobile(s): 1998 Cadillac Deville
    Join Date
    Aug 2012
    Location
    Tampa Florida
    Age
    36
    Posts
    808

    Re: 2004 N* fuel choices...premium wins

    try 100 octane racing fuel... it cost more
    CadillacLuke24 likes this.

  8. #7
    MoistCabbage's Avatar
    MoistCabbage is offline Cadillac Owners 10000+ Posts
    Automobile(s): Crimson 2001 Seville STS, 1990 Seville (RIP)
    Join Date
    Sep 2010
    Location
    East Boston MA.
    Age
    26
    Posts
    21,898
    The engine does not idle better, it's all in your head. Placebo effect.

    "Premium" fuel is not any "better" than "regular". There are no more additives, it is no cleaner, and it has no more hydrocarbons (energy content). The ONLY difference is its resistance to igniting under the heat of compression.

    The engine cannot sense what fuel is being used. The only time the PCM reacts to lower octane is IF AND WHEN detonation occurs, and that will a under high load, high RPM conditions. Idle is not even remotely close to causing detonation with lower octane. This has been discussed to death in lots of threads.

    ----------

    Quote Originally Posted by SUPER LAC DEVILLE
    try 100 octane racing fuel... it cost more
    Must be better then
    doc538 likes this.

  9. #8
    knotgoalie's Avatar
    knotgoalie is offline Cadillac Owners Fanatic
    Automobile(s): 04 DHS, 99 F150 4x4 SCAB
    Join Date
    Oct 2013
    Location
    Ontario, Canada
    Age
    58
    Posts
    272

    Re: 2004 N* fuel choices...premium wins

    Quote Originally Posted by basscatt View Post
    ---------------------------
    unless you are towing - or racing -
    you are wasting money buying anything higher 87 gas -

    you won't get any more power - or better gas mileage -

    as far as the "BUTT-DYNO" test goes - it proves nothing -

    but if it makes YOU feel better - go for it -
    the gas companies appreciate the extra money -
    90+% of my driving is done in a company vehicle (loaded 2013 Chrysler Town & Country, soon to be replaced with a 2014) and they pay the gas, etc. so when I drive my personal vehicle I can almost consider it a hobby. My personal fuel costs per year are minimal to say the least so I feel I can afford to experiment and evaluate without breaking the bank as it were, hence I will indulge my DHS as it warrants. I don't have kids or pets so I can spend whatever I feel like on my wheels. To each his own and here's to ya'.


    J.R.


    J.R.

  10. #9
    SUPER LAC DEVILLE's Avatar
    SUPER LAC DEVILLE is offline Cadillac Owners Enthusiast
    Automobile(s): 1998 Cadillac Deville
    Join Date
    Aug 2012
    Location
    Tampa Florida
    Age
    36
    Posts
    808

    Re: 2004 N* fuel choices...premium wins

    Quote Originally Posted by MoistCabbage View Post


    Must be better then
    YES!, For the Gas Companies... HAHAHAHAHA!!!

  11. #10
    basscatt's Avatar
    basscatt is online now Cadillac Owners 10000+ Posts
    Automobile(s): 89 Coupe DeVille, 95 Sedan DeVille, 03 SLS, two 02 DHS's
    Join Date
    Feb 2004
    Location
    Minnesota
    Age
    63
    Posts
    10,052

    Re: 2004 N* fuel choices...premium wins

    [QUOTE=knotgoalie;11312081]90+% of my driving is done in a company vehicle (loaded 2013 Chrysler Town & Country, soon to be replaced with a 2014) and they pay the gas, etc. so when I drive my personal vehicle I can almost consider it a hobby. My personal fuel costs per year are minimal to say the least so I feel I can afford to experiment and evaluate without breaking the bank as it were, hence I will indulge my DHS as it warrants. I don't have kids or pets so I can spend whatever I feel like on my wheels. To each his own and here's to ya'.


    J.R.


    J.R.[/QUOTE
    ---------------------
    well - in THAT case -
    there are LOTS and LOTS of products on the auto parts store shelves that you should try -

    and EVERY ONE OF THEM will work - just as well as using premium gas -

    enjoy!

  12. #11
    knotgoalie's Avatar
    knotgoalie is offline Cadillac Owners Fanatic
    Automobile(s): 04 DHS, 99 F150 4x4 SCAB
    Join Date
    Oct 2013
    Location
    Ontario, Canada
    Age
    58
    Posts
    272

    Re: 2004 N* fuel choices...premium wins

    Quote Originally Posted by MoistCabbage View Post
    The engine does not idle better, it's all in your head. Placebo effect.

    "Premium" fuel is not any "better" than "regular". There are no more additives, it is no cleaner, and it has no more hydrocarbons (energy content). The ONLY difference is its resistance to igniting under the heat of compression.

    The engine cannot sense what fuel is being used. The only time the PCM reacts to lower octane is IF AND WHEN detonation occurs, and that will a under high load, high RPM conditions. Idle is not even remotely close to causing detonation with lower octane.
    Do you not know your own vehicle closely enough to notice any changes be they performance, sound, fuel economy etc.? Perhaps the original owner of my car never ever wound it out or gave it the ritual shitkicking that a N* needs every once in a while to maintain but now I do and the benefits of that action may be starting to show up now with my driving style?

    The majority of new 04 DHS owners were older than the current demographic of Cad owners and were into the comfort/prestige more than the performance aspect of the vehicle and as such, although equipped with the venerable N*, they were not into the performance of the vehicle any farther than knowing what it "could do" and that was enough for them. The cars were driven in a grampa/gramma fashion which a N* simply was not designed/built/ intended for. Some of us younger (I'm 57) folks have to wind them out and make them sing every now and then so the premium fuel is the best slow burning insurance we have right now.


    J.R.

    ----------

    well - in THAT case -
    there are LOTS and LOTS of products on the auto parts store shelves that you should try -

    and EVERY ONE OF THEM will work - just as well as using premium gas -

    enjoy![/QUOTE]

    Sarcasm, right? You need to fire your writers, they're doing you no justice in this intercourse.


    J.R.

  13. #12
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    73,812

    Re: 2004 N* fuel choices...premium wins

    You really should not be able to tell the difference between 87 & 92. I run 87 and WOT is impressive (though that can be subjective). She has NO problem passing slower traffic.

  14. #13
    MoistCabbage's Avatar
    MoistCabbage is offline Cadillac Owners 10000+ Posts
    Automobile(s): Crimson 2001 Seville STS, 1990 Seville (RIP)
    Join Date
    Sep 2010
    Location
    East Boston MA.
    Age
    26
    Posts
    21,898
    I know my car quite well. Even of using premium fuel have you a whole 5 extra HP, you cannot feel or hear that difference in an engine that makes 275-300 HP. In a '60's beetle, maybe, but not in these cars. The demographic that the cars were designed for is completely irrelevant. Idle is totally and utterly unaffected, and any power difference to small to be noticed.

    I'm not saying you shouldn't use a higher octane fuel, it's your car, do whatever you'd like. But unless you have dyno slips showing a power difference, or have run several tanks of fuel under IDENTICAL conditions using different octanes, and have recorded a difference in MPG, there's nothing to support the claims that "premium" is better for a Northstar.

    ----------

    Quote Originally Posted by knotgoalie
    Some of us younger (I'm 57) folks have to wind them out and make them sing every now and then so the premium fuel is the best slow burning insurance we have right now.
    Insurance against what?

  15. #14
    knotgoalie's Avatar
    knotgoalie is offline Cadillac Owners Fanatic
    Automobile(s): 04 DHS, 99 F150 4x4 SCAB
    Join Date
    Oct 2013
    Location
    Ontario, Canada
    Age
    58
    Posts
    272

    Re: 2004 N* fuel choices...premium wins

    Quote Originally Posted by Ranger View Post
    You really should not be able to tell the difference between 87 & 92. I run 87 and WOT is impressive (though that can be subjective). She has NO problem passing slower traffic.
    Well Ranger, as I had stated earlier, I have no idea how the car was treated previously but since I have owned it I have subjected it to to the rigors for which the engine was designed and despite the decriers, I have found that so far the use of 92~94 octane gives allows the engine to give a noticeable/differential "push" @WOT over 87.

    Perhaps my driving style is the lynchpin given that I'm not especially easy on it as compared to the O.O. who paid over $65kCdn. new for it and very likely babied it. My relative "abuse" may be waking it up???

    It is what it is, I love my Cad, I went from my 85 Deville to an F150 for 7 years because of my retail business where I needed a truck but I closed the store recently and went back to Cadillac as soon as I didn't need the truck. Old habits die hard and truly, we don't have to justify them. My .02Cdn.


    J.R.

  16. #15
    basscatt's Avatar
    basscatt is online now Cadillac Owners 10000+ Posts
    Automobile(s): 89 Coupe DeVille, 95 Sedan DeVille, 03 SLS, two 02 DHS's
    Join Date
    Feb 2004
    Location
    Minnesota
    Age
    63
    Posts
    10,052

    Re: 2004 N* fuel choices...premium wins

    Quote Originally Posted by knotgoalie View Post
    Do you not know your own vehicle closely enough to notice any changes be they performance, sound, fuel economy etc.? Perhaps the original owner of my car never ever wound it out or gave it the ritual shitkicking that a N* needs every once in a while to maintain but now I do and the benefits of that action may be starting to show up now with my driving style?

    The majority of new 04 DHS owners were older than the current demographic of Cad owners and were into the comfort/prestige more than the performance aspect of the vehicle and as such, although equipped with the venerable N*, they were not into the performance of the vehicle any farther than knowing what it "could do" and that was enough for them. The cars were driven in a grampa/gramma fashion which a N* simply was not designed/built/ intended for. Some of us younger (I'm 57) folks have to wind them out and make them sing every now and then so the premium fuel is the best slow burning insurance we have right now.


    J.R.

    ----------

    well - in THAT case -
    there are LOTS and LOTS of products on the auto parts store shelves that you should try -

    and EVERY ONE OF THEM will work - just as well as using premium gas -

    enjoy!
    Sarcasm, right? You need to fire your writers, they're doing you no justice in this intercourse.


    J.R.[/QUOTE]
    ---------------------------
    Sarcasm, right?
    ME? - no way - what I posted is PURE FACT -
    CadillacLuke24 likes this.

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Bookmarks

Cadillac Posting Rules

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
Read about Lincoln | Buick | Kia Forte Forum
Need products for your Cadillac? Check out your options at the links below:

custom floor mats | Cadillac Chrome and Black Chrome Wheels | window tinting