Any increase MPG tips?
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 12 of 12
Northstar Engines and System Technical Discussion Discussion, Any increase MPG tips? in Cadillac Engine Technical Discussion; Different tires have made a difference on my car. Unfortunately my new ones have decreased the MPG. Does anyone have ...
  1. #1
    infin1ty is offline Cadillac Owners Member
    Automobile(s): 98 STS
    Join Date
    Jan 2004
    Location
    PA
    Posts
    42

    Any increase MPG tips?

    Different tires have made a difference on my car. Unfortunately my new ones have decreased the MPG. Does anyone have any tips for increasing their gas mileage?

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    danbuc's Avatar
    danbuc is offline Cadillac Owners Connoisseur
    Automobile(s): '87 Jeep, '10 Thruxton, '00 Duc 748, '01 748R (853cc)
    Join Date
    Mar 2004
    Location
    Mahwah, NJ
    Age
    29
    Posts
    3,703

    Re: Any increase MPG tips?

    Don't press the throttle as hard.....?

  4. #3
    WOTMODE is offline Cadillac Owners Fanatic
    Join Date
    Jan 2004
    Location
    Minneapolis area
    Posts
    117

    Re: Any increase MPG tips?

    Pushing vehicle with engine off will result in best possible mileage.

  5. #4
    JimHare's Avatar
    JimHare is offline Cadillac Owners Connoisseur
    Automobile(s): 01 Eldo ETC, 02 Deville SOLD!
    Join Date
    May 2004
    Location
    Salem, NJ
    Age
    61
    Posts
    1,815

    Re: Any increase MPG tips?

    Well, notwithstanding the excellent, though tongue-in-cheeky replies from the first two posters, here's what I've found to be efficacious:

    1) make sure tires are inflated correctly, or a pound or two higher than may be recommended - mfg recommendations are often towards the low side for ride quality. Going from say, 28 to 32 or 33 all around will get you something.

    2) Adjust your driving habits - racing from stoplight to stoplight, while fun, is hell on mpg - take off smoothly, with an eye towards getting the transmission into the highest gear as soon as possible. Coast down when you know you'll be stopping - everytime you have to brake, it means you didn't plan well enough ahead. Brakes on my cars regularly last 80-100K.

    3) Take any unnecessary junk out of your back seat/trunk - golf clubs, mother-in-law, cement blocks, etc etc. Less weight = better mpg

    4) Combine trips when you can. Short trips around town don't get the engine warmed up enough to reach max efficiency.

    5) Don't let it idle just to impress your friends. Also, a 'warm' up before driving off is not needed. Start it, count to three, and go. Easy on the gas for the first few minutes, as that's when the mix is richest, before the engine warms up.

    6) Make sure there's nothing blocking the air intakes/grill, etc. Frontal area blockage is bad.

    7) Keep off the A/C when possible, esp. at low speeds. Turnpike cruising is OK, I don't think the percentage hit is all that noticeable, and the closed windows probably make up for some of it. There have been some studies done as to whether the "windows open, A/C" off mode is better than "Windows UP, A/C on" mode, I don't think they're conclusive, but I'd bet that at highway speeds, the A/C efficiency hit is not all that bad - remember, you're dealing with an engine making 275-300 HP, so the 8 or 10 hp the compressor draws is not a big deal.

    8) Use the right oil as recommended.

    9) Turn on the DIC to show Instant MPG. After a few days of seeing how often and for how long you are at "9 mpg Instant" vs "54 mpg instant", you'll learn how to adjust driving habits to maximize the mileage you get.

  6. #5
    zonie77 is offline Cadillac Owners Connoisseur
    Automobile(s): 94 ETC,97 STS
    Join Date
    Sep 2003
    Location
    Arizona
    Posts
    3,531

    Re: Any increase MPG tips?

    Excellent post JimHare,

    I've seen articles that tested MPG on highway, AC on to AC off, with newer systems the mileage is definitely better with the AC on.

  7. #6
    CadillacSTS42005's Avatar
    CadillacSTS42005 is offline Banned
    Automobile(s): 2005 STS4 1SG: GM Acc Lights, Corsa, Platnium Grille, Volant
    Join Date
    Oct 2005
    Posts
    15,992

    Re: Any increase MPG tips?

    there are also a few mechanical things you can do to increase mpg

    1. Clean you TB
    2. Replace your fuel filter
    3. Replace your air filer
    (all apply when they are dirty otherwise theres no point in doing it)

  8. #7
    fpmesiIII's Avatar
    fpmesiIII is offline Cadillac Owners Fanatic
    Automobile(s): 1996 Cadillac Seville STS (167k)
    Join Date
    May 2005
    Location
    Western NY
    Posts
    473

    Re: Any increase MPG tips?

    good post Jim Hare.

  9. #8
    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
    73,376

    Re: Any increase MPG tips?

    Fuel & air filter will not improve milage.

  10. #9
    krimson_cardnal's Avatar
    krimson_cardnal is offline Cadillac Owners Enthusiast
    Automobile(s): 96DeVille
    Join Date
    Aug 2005
    Location
    NY Capitol District
    Age
    67
    Posts
    962

    Re: Any increase MPG tips?

    me thinks jimhare hit it - smacked it hard w/ the last point watch the numbers on the DIC

    check this for an outside point of view:

    http://www.inct.net/~autotips/mpg.htm

    i'm thinking that a clean air filter and fuel filter is going to help the cause, but driving habits are on top of the list...

  11. #10
    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
    73,376

    Re: Any increase MPG tips?

    A clogged fuel filter will reduce fuel flow. A clean filter will flow more fuel. Now don't get me wrong, I am not advocating a dirty fuel filter, but I don't see the logic in better milage with a new fuel filter.

    Likewise with an air filter. That was very true on a carburated engine, but not so on an injected engine. The MAF sensor measures the air flow and based on that information the PCM commands the injectors accordingly. Dirty filter = less air flow = less fuel.

  12. #11
    krimson_cardnal's Avatar
    krimson_cardnal is offline Cadillac Owners Enthusiast
    Automobile(s): 96DeVille
    Join Date
    Aug 2005
    Location
    NY Capitol District
    Age
    67
    Posts
    962

    Re: Any increase MPG tips?

    i hear you. i also read some where about a clogged fuel filter giving better mpg 'cause less fuel is delivered. that really blew me out.

    best mpg is from a well maintained engine/vehicle one should say, so's that's what i mean. keep it up to spec, purring like a kitty and don't drive like a maineeeack.

    interesting how this is becoming the concern w/ fuel costs going where they are.

    any feedback on the ethanol issues. what needs to be done to a NorthStar to get above the 10%E fuels. think GM is going to move that way??

  13. #12
    JimHare's Avatar
    JimHare is offline Cadillac Owners Connoisseur
    Automobile(s): 01 Eldo ETC, 02 Deville SOLD!
    Join Date
    May 2004
    Location
    Salem, NJ
    Age
    61
    Posts
    1,815

    Re: Any increase MPG tips?

    Quote Originally Posted by Ranger
    A clogged fuel filter will reduce fuel flow. A clean filter will flow more fuel. Now don't get me wrong, I am not advocating a dirty fuel filter, but I don't see the logic in better milage with a new fuel filter.

    Likewise with an air filter. That was very true on a carburated engine, but not so on an injected engine. The MAF sensor measures the air flow and based on that information the PCM commands the injectors accordingly. Dirty filter = less air flow = less fuel.

    Exactly right - clogged filters will not do anything measureable to affect overall MPG. I had a 1973 Chrysler Newport once that had never had the fuel filter changed. I know this because it had belonged to my uncle and he willed it to me before his demise. I saw that car every day of it's life. On one of my rare days of actual energetic movement, I decided to change it. The filter was literally clogged full of sediment. Looked like it had been submerged at the bottom of the Okeefenokee Swamp for 10 years. The new filter went in, and the mileage didn't move a bit. This was in 1978 and I don't believe things have changed re: fuel filters since then.

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