What kinda gas mileage should i be seeing out of my 91 CDV 4.9? Im gettin 12 city and 21 highway and thats driving like a legit grandma. Everyone post your mpg's or in some situations gpm's. 
Post Your Gas Mileage!
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BMW 750li, MB S550, Bentley spur and Escalade platinum
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i got 29.8 Mpg in highway. Averal speed is 100km.h
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This same thread title (or close) comes and goes every year - go back in time and find one to bump and update. Of course the car, year, engine, altitude, mileage, driving habits, and country (gasoline quality) all make a difference..................What kinda gas mileage should i be seeing out of my 91 CDV 4.9? Im gettin 12 city and 21 highway and thats driving like a legit grandma. Everyone post your mpg's or in some situations gpm's.
Yeah I expected similar results... I just wish there was something wrong with it that I could repair and pick up like 5 or 6 mpg. Its alright though thats the price you pay for luxury.
I am getting 16 MPG. Driving both city and highway about equally every day.
'94 SDV 4.9
20.8 mpg's with mostly country hwy and small town driving.....and the cool thing is i'm not even trying!!!
20.8 mpg's with mostly country hwy and small town driving.....and the cool thing is i'm not even trying!!!
92 DeVille
18/19 around town
20+ on the freeway
Question... How accurate are the on-board computers at calculating MPGs? Mine usually reads anywhere from 14-19 averaging, but I don't think the computers calculates in things like idling, waiting, or otherwise having the engine running without driving.
18/19 around town
20+ on the freeway
Question... How accurate are the on-board computers at calculating MPGs? Mine usually reads anywhere from 14-19 averaging, but I don't think the computers calculates in things like idling, waiting, or otherwise having the engine running without driving.
20 mile commute city/highway to work averages 23 on the button. Highway, if I run 65 I get 28-29
I'm averaging 16mpg around town and 25mpg+ highway, with cruise-control engaged.
I believe the onboard computer does factor in idling, because when I'm stopped I can see it drop rapidly (after I recently reset it and I reset it every time I refuel). Also, when I hit Manhattan after 50miles on the Long Island Expressway, there's a noticeable drop in my readings.
-Drew
I believe the onboard computer does factor in idling, because when I'm stopped I can see it drop rapidly (after I recently reset it and I reset it every time I refuel). Also, when I hit Manhattan after 50miles on the Long Island Expressway, there's a noticeable drop in my readings.
-Drew
85 Coupe Deville 4.1 V8 & 4.3 V6 Deisel & 1970 Eldorado
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776 Posts
The computer keeps track of how much fuel is used by totalling up the fuel injector on time. The fuel flow through each injector is a constant and is a known value. As long as the injectors are clean and the fuel pressures are correct, It is a simple matter for the computer to track the amount of fuel passing through the injectors. This fuel amount is calculated against the total mileage travelled to give the average mileage. Instant mileage is calculated using the injector on time against the vehicle speed over a pre set time period.. Any time the engine is running the computer is totalling the fuel used. That is why the average mileage will change if allowed to idle long enough. (Especially if the trip computer was recently reset)
No. Same ballpark with my STS - same drivetrain. We have the 300 hp engine with a 3.71:1 final drive. Your tach should read 1980 rpm at level road 60 mph.
~14 or so in town,
~18 - ~20 suburban/near rural
24.8 - 25.3 long haul Interstate.
All on the recommended 87 octane (Shell) with a 20 oz. jug of Chevron TECHRON every 5,000 miles.
I just checked my DIC for the average MPG.. It read 14.8
I use 87 octane
I use 87 octane
2003 Cadillac DTS (VIN 9) 300hp Engine 54,XXX Miles
93 octane fuel
Haven't done city driving do idk yet.
Highway Driving - 27.6 MPG Driving 55 MPH, RPM At About 1,750 RPM.
~Ways To Get Better MPG~
Change Fuel Filter
Use Higher Octane Gas
Change Intake Air Filter
Change Old Spark Plugs
For CNP (Coil Near Plug Ignition) Check Spark Plug Wires For Resistance
Properly Inflated Tires
Take any UN-NEEDED weight out of the vehicle.
Ease On Acceleration (Between 1k-2k RPM) No Need To Pound The Throttle During City Or Highway Driving Cruise Up To Proper Speed.
Ease On Braking No Need To Suddenly Harshly, Press On Brake Pedal Ease Onto The Brake Slowly.
During Summer Driving Use AC With Windows Up. Instead Of AC Off With Windows Down. To Reduce Less Drag On Your Car.
^ Hope These Help For PPL Trying To Get Better MPG's I Probebly Forgot Some Stuff But Heres A Good Star.
93 octane fuel
Haven't done city driving do idk yet.
Highway Driving - 27.6 MPG Driving 55 MPH, RPM At About 1,750 RPM.
~Ways To Get Better MPG~
Change Fuel Filter
Use Higher Octane Gas
Change Intake Air Filter
Change Old Spark Plugs
For CNP (Coil Near Plug Ignition) Check Spark Plug Wires For Resistance
Properly Inflated Tires
Take any UN-NEEDED weight out of the vehicle.
Ease On Acceleration (Between 1k-2k RPM) No Need To Pound The Throttle During City Or Highway Driving Cruise Up To Proper Speed.
Ease On Braking No Need To Suddenly Harshly, Press On Brake Pedal Ease Onto The Brake Slowly.
During Summer Driving Use AC With Windows Up. Instead Of AC Off With Windows Down. To Reduce Less Drag On Your Car.
^ Hope These Help For PPL Trying To Get Better MPG's I Probebly Forgot Some Stuff But Heres A Good Star.
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