Why does my gas mileage DECREASE after an oil change?

Question:
It seems like every time I change the oil in my car, I get WORSE mileage than before the change. What can cause this, and how can I fix it?

Answers:

What can it be that is making my car use and burn gas?

Should not be. There must be other factors, such as climate temperature change or vehicle has more load in it or driving over a different route. As far as the oil goes if you went from a 5w30 weight oil to a 10W30 oil then that could cause a slightly higher gas usage due to the higher viscosity of the oil which creates more drag on the engine. When your oil is dirty and at the point you need to change it chances are the viscosity is now lower due to contamination thus the less drag on the engine to operate, this could show up in the mileage. All in all the difference due to the oil alone is very slight and I would say very difficult to measure as a true comparison. As mentioned at beginning there are other factors that have a greater effect on the mileage. Gasoline octane is also a factor, hope this helps. Tire air pressure can be a big factor.

i have a 1998 ford escort 1.8 ltr turbo diesel lx where is the central locking master controller for key locki

maybe going to the wrong place .

52 astra reverse light switch?

How are you measuring this, on a dyno with accurate fuel measurement, or guessing?

What are the dimensions for the flex pipe on a 1993 Toyota Celica ST? Is it possible to replace just the flex?

got me dude, millage should go up at least. what oil are they dumping into your mill?

how to replace alternator ford ecort 1600 with air conditioning 'S' registration?

are you acualy takeing milage/gallon with odometer...it shouldent change

1993 Lexus GS 300 sometimes drives rough. Sometimes it shakes even when idle. transmission is good.?

millage multiplied by oil change equal to more fuel consumption.?

My car breaks produce a squicking sound everytime I step on it? What's wrong with it?


millage. should increase if I never change the oil in my car?

Where can i find 93 GMC LB4 4.3L V6 TBI Crate engine for sale and delivery?

if its the kinda place that checks your air pressure for you while doing the service, they are probably letting to much air out of your tires is where i would start. ive seen many places that set the pressure to the "cold fill psi" not taking into account that your tires are warm from driving. they let air out, and your gas mileage suffers. i would check that first. if you do your own oil changes, it may be the weight of oil you are using. use the manufactures recommended weight for your vehicle.
More Questions & Answers ...

  • 2000Buick Park avenue#2?
  • Check engine light comes on and off, heat went out, hard starts some mornings.?
  • In a 98 chevy malibu 2.4 engine, how is it that the coils provide like 40k volts of electricity to the plug?
  • Are the quick CV boot replacements worth it?
  • Need new doors on car?
  • how often should i change oil in a yfz 450?
  • I have a toyota coralla t3 and now it has a starting problem when i am going to start t?
  • Spark plug question for an 1994 Olds Cutlass Supreme?
  • Is their a big difference between 245/75/16 & 265/75/16 Tires?
  • What is wrong with my 2001 Dodge Ram? (85,000 miles)?
  • This article contents is post by this website user, CarQnA.com doesn't promise its accuracy.


    Copyright 2006-2008-2007 CarQnA.com. All Rights Reserved.