Gas miles -- Standard DeVille vs DTS
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
Results 1 to 8 of 8
Northstar Engines and System Technical Discussion Discussion, Gas miles -- Standard DeVille vs DTS in Cadillac Engine Technical Discussion; My wife and I rented a standard DeVille (2004) on a recent trip. We liked it well enough to buy ...
  1. #1
    K0UZE is offline Cadillac Owners Member
    Join Date
    Jul 2004
    Location
    Minneapolis, MN
    Age
    67
    Posts
    14

    Gas miles -- Standard DeVille vs DTS

    My wife and I rented a standard DeVille (2004) on a recent trip. We liked it well enough to buy an '02 DTS with about 15K and the 100K 6 year warranty. It was very easy to get about 25 mpg in the rental vehicle. I was a bit unhappy to find that the DTS does about 20 to 21 when driven similarly. Then I had the DTS in for some minor warranty work and the dealer gave me another standard '04 DeVille. Again, 25 mpg pretty standard. I mentioned the lower mileage to the dealer and they recommended a fuel injector cleaning. It made no appreciable difference. So what's the story? Do the '04 models get better mileage than the '02s...or does the standard DeVille do better than the DTS? And in either case, any theories on why? I love the DTS but I am not too happy about giving up 4 to 5 mpg. Any observations will be much appreciated. Thanks.

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    Ranger's Avatar
    Ranger is online now Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    73,353

    Re: Gas miles -- Standard DeVille vs DTS

    What engine does the DTS have? If it has the 300 Hp then it will also have the higher final drive ratio and the milage you are getting is about right for that engine and final drive.

  4. #3
    Ralph's Avatar
    Ralph is offline Cadillac Owners 10000+ Posts
    Automobile(s): Cadillac
    Join Date
    Mar 2003
    Location
    Saskatchewan, Canada
    Posts
    16,028

    Re: Gas miles -- Standard DeVille vs DTS

    Driving my Dad's 2003 DTS home (maiden voyage) it averaged 25-27 highway, about the average for my 1991 4.9 also.

  5. #4
    K0UZE is offline Cadillac Owners Member
    Join Date
    Jul 2004
    Location
    Minneapolis, MN
    Age
    67
    Posts
    14

    Re: Gas miles -- Standard DeVille vs DTS

    It's the 300 hp version. Logically, one would expect a slight degradation in mileage with the more powerful motor, but that still doesn't square with Ralph's report of 25+ mpg on the road. Like I say, I get about 21 or so. Perhaps they fiddled with the engine management programming to get better mileage starting with the '03 models.

    I have not been able to find the final drive ratio in the owner's manual, either.
    Of course, lower gearing could also adversely affect mileage.

    This is certainly a small gripe, because otherwise the car is really great.

    Thanks for the feedback.

  6. #5
    gserep1 is offline Cadillac Owners Member
    Join Date
    Jan 2004
    Posts
    42

    Re: Gas miles -- Standard DeVille vs DTS

    Are you using the same type of gasoline? I understand that the newer versions of the Northstar use regular gasoline, while older engines use Premium. I have a 98 STS, and cannot use regular gasoline without sputtering and loss of power.
    GSEREP1

  7. #6
    Ralph's Avatar
    Ralph is offline Cadillac Owners 10000+ Posts
    Automobile(s): Cadillac
    Join Date
    Mar 2003
    Location
    Saskatchewan, Canada
    Posts
    16,028

    Re: Gas miles -- Standard DeVille vs DTS

    Could viscosity of oil be affecting the mileage? Tire pressure? It's my general understanding that thicker oil reduces mileage. Just a thought.

  8. #7
    Ranger's Avatar
    Ranger is online now Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    73,353

    Re: Gas miles -- Standard DeVille vs DTS

    Quote Originally Posted by gserep1
    Are you using the same type of gasoline? I understand that the newer versions of the Northstar use regular gasoline, while older engines use Premium. I have a 98 STS, and cannot use regular gasoline without sputtering and loss of power.
    GSEREP1
    You can use reugular. I use it in my '97 and don't even notice the difference. The knock sensors will retard the spark as required. If you are going to race it and want absolute best performance, that is another story but for general driving you should have no problem with regular.

  9. #8
    gserep1 is offline Cadillac Owners Member
    Join Date
    Jan 2004
    Posts
    42

    Re: Gas miles -- Standard DeVille vs DTS

    EVEN in a 98 STS? It would be nice if I could run regular gas. I am going to do a top end cleaning before I change the plugs and wires. Hopefully this will help decarbonize the heads and allow the use of regular gasoline. I'll give it a try, but if performance drops off significantly, or fuel mileage drops too far, I will switch back to 89 or Premium.
    GSEREP1

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