Cadillac CTS-V Forum banner
1 - 7 of 7 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter · #1 ·
Yup. 2009 CTS-V 31k miles. Don't ask... Not much of a car guy - but I "get-it!"... punn intended. Question: Had to have a new fuel pump and sender kit installed... and all new spark plugs. The car sat idle for a few years. First drive yesterday; filled it with 91 premium, 1/4 tank later I'm looking at 19.4 miles of driving with AC on (... 80 miles per tank!?!? Really!?!?!). What am I missing... and/or what am I asking the mechanic who just set it up for me? Thanks in advance. And thank you Russia:(
 

·
Registered
Joined
·
55 Posts
For doing 30-40 passes at the drag strip I’d say you’re crushing the mpg! ;) Sorry for your family loss but do enjoy the car. I don’t have a theory on your early observation but I would inspect the heck out of your tires as it sat (dry rot) and your brakes (presumably mechanic did that tho) then put a few more miles on it, hit some hwy miles after thorough warm-up and open the car up, high rpm pulls a few times. Then observe mileage. But I bet a bunch of other guys on here have sound theories and experience to offer!
 
  • Like
Reactions: 2009 CTS-V Newbie

·
Premium Member
V Coupe Pedal car
Joined
·
2,819 Posts
Welcome to the Modness! First, Never try to calculate mpg or range based on a fraction of gauge travel... that's madness. The V will get awful-enough mileage without crippling your hopes with Ouija-board-level calculations!!

The CTS-V is an amazing Performance sedan and it will always consume atrocious amounts of fuel... but if you TRULY GET it, you will stop caring about MPG. On the highway, expect maybe 17.5 tops with a bone stock V. Every other operational mode will get worse than that.

Also, stop running 91 octane premium! Use 93 octane every chance you can. At some point, if you pursue modding (and who doesn't?) you can add the proper tune and the capability of running a flex sensor and E85 fuel for a whopping HP increase. And THEN wait 'til you calculate THAT mileage!
 

·
Premium Member
V Coupe Pedal car
Joined
·
2,819 Posts
Also, on a more serious note: You had someone working on the pump/sender. It is imperative that they did it correctly because the fuel tank on the V requires special attention in that the tank is effectively separated into two tanks by the driveshaft "hump" in the center of the tank. Because of this arrangement, there are TWO sending units, one each side of the tank and the pump 'module' (which is on the passenger side) has two regular fuel pumps plus a little jet pump that pumps fuel constantly from the driver's side over to the passenger side where the main pumps and fuel pickup are. The computer averages the two sending units' signals to show how much total fuel you have. If this transfer arrangement isn't working or connected properly, you will appear to get really awful mileage as you would only be using fuel from HALF of the tank. You will also be on a tow truck soon as you will run out of gas even though the senders "see" half a tank of gas. You should (seriously) quiz your mechanic to see if he understands the V's weird pump and operation. If you get a blank stare... fill up soon.
 

·
Registered
Joined
·
2 Posts
Discussion Starter · #5 ·
Oh Lord. Okay... this is a bit of a rabbit hole, but having thoroughly enjoyed my 540 years ago... I'll take the dive. I suppose I need to find a specialist in the LA area basin. Thanks so much for the info.
 

·
Registered
Joined
·
2,002 Posts
Also feel free to post in the specific forums when you need help and usually you’ll get some good advice!


Sent from my iPhone using Tapatalk
 
1 - 7 of 7 Posts
Top