Need your advise.
I have a 08, 528i that I used before to go work and I was getting an average of 20 MPG.
Now I only use it to go to the store or take my kids to school very short trips and the average gas millage is 14.4. Last year I replaced the spark plugs and all the air filters.
I own this car for 3 years and I bought it with 61K and now it has 114K. It is my first BMW and love it but I think I should be getting a better gas millage. Any advice will be very appreciated. Thanks

 

Hello, on your short trips, do you "get rolling" at all, or is it block to block? have you taken the car on any highway trips to see what mileage it gets?

I have a 528i too and it gets 25mpg of combined driving.

 

Thanks for your answer.
It is mostly block to block and I am not a slow but neither an aggressive driver.
I used to fill up the thank and reset the mpg right before taking a 2 hours trip on the freeway and I will get 25 to 27 mpg but when I combine 50% freeway and 50% city I only get about 19 mpg. Now I used the car for very shorts trips for the last 2 months and I been getting and average of 14 to 17 mpg. I know that the air on the tires need to be correct I already inspect them and I been using gas from Chevron. I noticed that car started to getting this worse right after taking it to dealer I was complaining that car was shaking and idle was up and down, so they rise the idle and performed a fuel injector cleaner service, I was happy for the car not shaking any more but maybe by rising the idle it got worse on mpg?

 

I don't see how a few more RPMs when idle would noticeably hurt your mpg. What octane fuel are you running? what tire pressure are you running?

I use 93 octane British Petroleum gasoline, it's the highest octane in my city. I run 33 psi front and 35 psi rear.

I can see how block to block traffic is the worst,

 

I've noticed better MPG on the highway running high octane fuel. Might see small improvements in the city as well. Also more tempting to get on the pedal too though.

 

I am using 32 psi in the front and 36 psi in the rear.
I been filling up the thank using 91 always I think here in CA. is the highest we can get.

 

So, this guy buys a VW Bug because it is EPA rated at 25 MPG. In short orde her is repeatedly taking the vehicle back to the dealer loudly complaining that the mileage is terrible.
On his third return and out of desperation, the dealership disconnects the fuel line from the tank and rigs a one gallon fuel can. They drive the car to the limits of the fuel to find that the mileage is precisely 25 MPG.

The dealer asks the customer: How do you drive this vehicle? I deliver U.S. on a rural route box to box!

 

If your drive is too short, your engine won't get up to temp, which will decrease your mileage.

 

might want to check O2 sensors.. other than that, I have my tires inflated to 38psi front 40psi rear. On my last tank I averaged 21mpg (90% freeway) and normally I average 18mpg (combined city / fwy). I'm in a 550i though... car computer says I average 20.2mpg, but car computer is a little inflated IMO

 

If you drive an automatic you might want to ask the dealer if they changed your VO/FA code. There is a code which at a light mpg cost improves the start stop delay and/or stutter.