question about battery

[spuka02]

my car has 48,800 miles on the clock and is 2005 maxima and it still has the original battery on it . The car drives and runs well but there is a little delay when i start the car so i am thinking maybe i have to replace the battery now that car is almost five years old all the lights are working fine but i been getting poor gas mileage only 15.7 per gallon my tire pressure is good at 35 psi and i have no check engine lights on maybe i need to replace my battery any advice would be appreciated thanks in advance .

[MinisterofDOOM]

Battery will not affect fuel milage. The fuel milage issue is a sign of some other underlying problem...maybe bad O2 sensors or something. Is your check engine light on at all? You should be seeing low-20s MPG combined at worst, low 30s on the highway.

By delay, do you mean the car cranks several times before starting, or that you turn the key and nothing happens for a moment, THEN the car starts cranking?

I know the battery in my dad's '04 died very early. Much earlier than 48,000 miles. That may not mean anything, but is worth mentioning.

[spuka02]

No the delay is not too serious it just doesn't start nice and quick like a fairly new car does , as far as the mpg concern i am reaching the 3000 miles and is almost time for an oil change i don't think is a bad 02 sensor because i would get a check engine light on but i will put it on the diagnostic to see which sensor if any needs to be replace

[NutriaforBreakfast]

Could be the car key switch. I went through problems with my95 Max. The mechanic put a new one in for $100. Try starting thecar with different pressure on the key and see if it starts better. Before my repair, the car seemed to start better if I turned the key assemblytoward the wheel a little more rather than straight down like normal.