What would cause my 03 R53 to only get 18 mpg? Yes, the AC is on but 18!

 

any more info on your commute? getting 18 with AC on in the city? Highway? mix?

 

AC on, around town mostly but I live in a rural area.

 

if your doing a lot of short commutes that include a lot of stopping, im not surprised at 18 mpg. if your doing like 45 for 10 miles, that's when I would be concerned.


when running the AC the motor has to work harder to spin the SC and the AC compressor. requiring more fuel, around town its better to have windows down. but its always worth to check your plugs and air filter to make sure those are looking good to allow better combustion

 

Thanks Salty, I will check on those things.

 

18 is pretty dismal. I was living in the DFW area and not commuting on highways, all stop-go on surface roads, and still getting low 20s. Granted, that's with the opposite of spirited driving—shift at about 2500rpm. Now that I'm back to western PA, where my commute is all highway, I'm up to 28-29mpg regularly.

 

Driving like an AZZ.....that can drop mpg to 18 fast....
will be a fun 18 mpg though....

If there is an issue...like a sticky brake caliper, it might cause low mpg....one rim dirty?
Using 91+ octane right? Going cheaper will drop mpg if you are lucky...if not lucky will burn a valve.
What rpm are you shifting? Try a tank, going no higher the 4500, with most shifts at 4000....
When in good commuter mode, I could get 29-30 mpg daily...but if I drive harder, could do lots worse...
One more though...
Any mods on the car? Might want too look under the intercooler...see if the injectors are stock...
You could have bigger injectors on the car...untuned.

 

forgot about the sticky brake caliper. ive gotton 18 mpg once, but that was me hammering down to the store a few times for tools to fix my bike, but that was only a short while. I know that if I was driving up and down a strip at a car show id be getting roughly 15 mpg. if I was driving around boston or NYC im sure I would be in about that range is I drove everyday. daily I get about 25-27 and that's spirited driving

 

Good news, I checked again today and got 24 mpg! I'm putting all new rotors and pads on soon so I'll also check the calipers. Since this is a new to me car, I don't know what has been done or not done, so it needs a good going over. Peace,

Royal