Disa MPg improvment

[FredRC]

In a scale of 1-10 how much a shot DISA valve can hurt MPG.

Ever since I bought the car it has very poor MPG, I`ve already addressed Vacuum leaks and Vanos seals, changed oil, air and fuel filters and CCv.

I do mostly city driving and Brazil`s gas has 20% of ethanol mixed to it.

The only thing I haven`t touched its the DISA valve, and its flap its broken, can I expect a huge improvement in MPG after its been fixed ?

[pegcity]

Sorry to say after 3 Bimmers they suck in city driving, my car gets double the mileage on the highway.

There are improvements but it will never be awesome.

[bullard123]

Just curious how many mpg are you getting according to the computer? Mine is reading 20.6 mpg. I have replaced my sparkplugs, stock air filter with a high flow K & N filter and my Vanos Seals. I also plan on replacing my precat o2 sensors soon.

[champaign777]

300 miles on tank in city , but i am doing very short trips 2-3 miles each

[FredRC]

Just curious how many mpg are you getting according to the computer? Mine is reading 20.6 mpg. I have replaced my sparkplugs, stock air filter with a high flow K & N filter and my Vanos Seals. I also plan on replacing my precat o2 sensors soon.

Well including the other issues I mentioned, I already changed spark plugs and pre-cat 02 sensors as well.

My city has a pretty heavy trafiic you rarely keep your car over 40mph for more than 1 minute straight.

That being said I usually get 9.5 to 11.5 MPG in the city. Seem a lot for a 530i... and the only thing that comes to my mind after addressing all those issues is the shot DISA Valve.

[fudman]

A new DISA valve should not make a huge difference. The DISA controls the length of the intake manifold. It increases the length to increase torque at low reves and decreases the length at higher rpm for maximum HP, all by closing and opening the flap. I believe your driving conditions are why you have poor gas mileage.

[FredRC]

A new DISA valve should not make a huge difference. The DISA controls the length of the intake manifold. It increases the length to increase torque at low reves and decreases the length at higher rpm for maximum HP, all by closing and opening the flap. I believe your driving conditions are why you have poor gas mileage.

Most likely, I'll keep searching for ways to improve tough... :D

[bullard123]

Most likely, I'll keep searching for ways to improve tough... :D
It wont hurt if you tried the complete fuel system cleaner in the bottle as well. I used seafoam shortly after I bought my car and I just used the Lucas complete fuel system cleaner 6,000 miles laer. Have you tried cleaning your Maf as well?

[AnotherGeezer]

Automatics tend to do worse than manuals in the city. Remember, these are fairly heavy 4-door sedans. My worst mileage is similar to Champ's as I normally only do 2-3 miles trips for work unless I have somewhere to go. I average 21 in the city and 32 on the highway.