miles per gallon

topboss718 · #1 (**permalink**) 11-03-09, 02:06 PM

ok i got a 2001 cadillac seville sts now the specs say im suppose to get 17miles per gallon city and like 24 mile per gallon highway and im from new york so its mostly city miles but my problem is that it seems im geting from 5 to 7 miles a gallon lol my engine is clean not blowing out white smoke so its not spitting out oil or gas when i changed my spark plugs it was burning fuel normally i even showed a mechanic and he said its burning it normally i told him im getting like 7 miles a gallon for city and he said the northstar engines are gas guzzlers and dont believe the specs is he correct and am i suppose to be getting 7 miles ger gallon city ???

submariner409 · #2 (**permalink**) 11-03-09, 04:07 PM

In NYC I can believe the 7 mpg. Look at it this way: You fill up and reset the average fuel mileage (the instant readout is fun to watch and useless) and go for a drive on the Merritt. You go a half hour and get to 22 mpg. You get caught in a typical Friday PM backup at a fender bender. You sit, idling, for a half hour. You average fuel mileage now drops to 11 mpg (half hour at 22, half hour at 0 = 11 mpg.) It doesn't take too many slow/traffic jams to ruin average mileage.

Your car will get 17 - 19 near suburban, 23 - 25 on the open Northway.

Just for grins and kicks, start the car and remove the engine beauty cover. See the small dome with vacuum line in a receptacle in the fuel rail back on the right rear (looking from the bumper straight back) ? Pull that vacuum line off for a few seconds - any fuel in the connector nipple or vacuum line ?? If so, the FPR (Fuel Pressure Regulator) is faulty. Easy replacement www.rockauto.com. $45 and 15 minutes.

Ian-STS99 · #3 (**permalink**) 11-03-09, 04:13 PM

Sub is correct with this, I live in Maine and get around 14 - 18MPG in town (Portland), if I use HWY to go some place I can get around 28MPG, if in town (Boston or Concord) I end up with 10 - 11 MPG.

topboss718 · #4 (**permalink**) 11-03-09, 04:40 PM

thanks guy i feel more secure about my car now lol
one more thing someone told me its not good to warm up ur car if its year 96 and up just warm it up at the time it takes u to put ur seat belt on and then go i always warm it up for like 6 to 10mins when i first start it, is it best to do so or not ?

STSS · #5 (**permalink**) 11-03-09, 04:48 PM

You dont need to warm it up, just start it and drive. I try not to rev it too much (<4 or 5K RPM) before it reaches operating temp, but that is the extent of my warmup.

eyekandyboats.inc · #6 (**permalink**) 11-03-09, 06:00 PM

after driving my cars around my town for a while i got about 10 .5 avg mpg they way i drive. and this is no traffic like NYC taffic thats for sure! so your about right.

also you dont need to let it warm up all that much. it only takes about 3 seconds for the full pressure oil system to s do a full oil circulation. after that you are good ( beleive it or not). also you can just wait afte the startup for the idle to drop ( about 3-7 seconds depending on your temperature outside) once the idle is down you are good to go.

submariner409 · #7 (**permalink**) 11-03-09, 06:13 PM

yep.......With today's oils and filters you're much better off to start the engine, adjust the mirror, snap the seat belt, set the radio volume and drive.

Extended warmup is actually very hard on a modern car engine - as STSS posted, don't try to outrun the Lexus until after 20 minutes of driving.......

FWIW, one of the absolute worst things you can do to an engine in a car which is laid up for a while - more than 4 days - is to start it and let it idle until "warm", then shut down. Nothing gets warm enough to reach operating temperature and the inside of the engine fills with condensation moisture and blowby combustion acids. Turn it off and leave it off (with a battery maintainer connected) until you're ready to drive for a while............

johnny kannapo · #8 (**permalink**) 11-04-09, 10:05 PM

When you sit in traffic with your foot on the brake, you are getting a big "0" mpg. If you sit at the stoplight 2 minutes then drive 1 block to the next 2 minute light not even hitting 25mph.....average that out. Thats over 4 min. to go 1/10th of a mile. On the hwy you can easily cover 4 + miles in less time. Do the math...PERHAPS THERE IS A NEED TO BE THE ONE TO REACH THAT NEXT STOP LIGHT FIRST, so you get that feeling of accomplishment. This behavior is bad for mileage. I have always used 18 to 22mpg cold, & around town, 26 to 28+ hwy. The mpg data right there for you is cool.