my car is basically stock. in the past year or so, my mpg went from a consistent 22.5 to now hovering around 19.5. nothing has changed, not my driving style, not mods, etc. back in january, the dealer told me my battery was getting weak. could a weak battery cause such a drastic drop?

 

wow. definately not. maybe plugs and wires or a/f sensor.

 

The battery may but it could be tied to an alternator going bad also. Extra load with the alternator could cause the mpg to be lower if it trying to keep the battery charged.

 

No

 

lol@ this thread

answer is no

 

battery only affects MPG in a prius

 

lolol

 

Sorry man it was funny!!No impossible.

 

no on this also.

 

did someone tell u that ur battery can affect ur mpg cuz if so, i wouldnt rely on him anymore... just saying... imo and all...

 

Hellz naw batt. Is only there to start the car after that everything else is up to the alt. And the battery is just along for the ride

 

IF the battery is near dead or has some dead cells the alternator would have to work much harder to charge the battery thus applying more load on the engine and slightly lower gas milage.

 

Do you mean that it would slightly raise idle or actually create more load while driving?

Generators have no gears and cannot create more load when called for by the motor.

It's free spinning and does not have a clutch like the a/c compressor.

I can run some logs to prove it to you