bad gas milage

[dapope]

ok so i ave a front mount intercooler vibrant ehuast injen intake and bov and i get like 15 miles a gallon highway driving under boost,...this cant be normal what do you think

 

[fr0st]

highway driving under boost? thats like , not 55 MPH right?

 

[BOOSTR]

You are either driving extremely hard and have upped the boost quite a bit or you need to replace the basics: plugs, pcv, air filter etc. 15 mpgs on the highway is extremely low. I can get between 24-31 on the highway depending on my driving style for the tank, and that is at 75+ mph.

 

[dapope]

its not under 55 mph lol...i just tried instead of hammering the gas lol i slowly creep into it so it stays in vacumm, i could hit upwards of 80 without even touching boost...i have new plugs in, should i go a stage colder, because i plan on doing the unichip, also i think i might replace the pvc and o2 sensor

 

[orlandomsp]

What kind of gas are you using?

 

[dapope]

93 octane always

 

[Kansei]

I thought my car (with msp turbo kit + corksport downpipe, full 2.5" downpipe-back exhaust, FMIC, 6-8psi) got bad mileage, but with lots of fun boosting on backroads tearing up my snow tires and maybe 20-30% highway driving to and from work and getting stuck in gridlock traffic on the way back into the city after work.. I still managed 18mpg on my first couple tanks since being boosted.

What heat range plugs are you using? stock is 6, and that's what I'm running.

p.s. welcome to the forums, I'm from CT too (though in Rochester at school).. check the NEPOC subforum, near the bottom of the forum index, lots of Mazda people in New England

 

[dapope]

right now there stock plugs, and im not in ct right now lol im stationed at fort drum new york

 

[25FConv]

I swapped my ES engine for an MSP and I am getting the samething...15mpg...i have and injen intake, msp exhaust, hiboost fmic......nuthing to drastic and i am getting the shittiest gas mileage in the world.....i just replaced the spark plugs with some ngk iridiums, a new pcv valve to the millenia s pcv valve......what can i do?

(pissed)

 

[Little Beavis]

That's pretty rough. . .I'm pushing a whole lot more horsepower and still getting 29 mph on highway cruises and 23 on my way to and from work (lots of stop and go in Chicago traffic). 15 and 18 is crazy. Maybe it is time for a real computer. . .call NSNmotorsports and get a Microtech. . .you can apparently pay for it with the gas you'll save!

 

[SeR_Cyclops]

with just a aem intake i still get 27 it added 2 mpg when i added it so i started at 25 now im at 27... somthing is not right.

 

[yashooa]

Man, I feel for you. I have an MPI and a lot of other stuff and if I keep my foot out of it and granny drive I get as high my all time best 37MPG!
Now on those days I hammer the s*** out of (granted my clutch sucks right now ) I get about 360-380 miles out of 12 gallons.
After all the mods I thought my mileage would suffer but it has been the exact opposite. I guess a better tune returns better mileage.
This is based on my 104 mile round trip commute to work and back.

My mileage did suck HORRENDOUSLY with a bad o2 sensor.

 

[hotrodf1]

Just a thought,

The How-to section lists cleaning the EGR valve - I was reading that thread and some guys said they got better mileage after the clean. Plus better idling, etc.

If you haven't done this yet, you probably should. I will be doing it when I change my mani out for the 626 version.


worth a read:::
http://www.msprotege.com/forum/showthread.php?t=94788

 

[25FConv]

its not the case with mine. I put in the protege garage intake mani....with a new egr pipe and valve.....but i still get some bad milage. i would be getting a little more than 15 mpg.

i have been searching around for the answer but i have yet to get anything back.....still open to suggestions though.

 

[hotrodf1]

When you pull the plugs what do they look like?

If you are running so ridiculously rich, I woudl think the porcelain on the plugs should be black.

I'd check that to make sure.

 

[Kansei]

Yeah it's pretty much usually black

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[Kansei]

^^ I think that might have been from when I tried to run a 6 heat range plug when I wasn't turboed though.. not exactly sure. but yes, black is the color of choice for a Protege spark plug.

the upper plug doesn't have more than 2k miles on it.. as you can see from the electrode it isn't worn down, just incredibly filthy.

 

[cold_rabbit]

hell i get around 600 K to a tank on premium , your milage sux

 

[Karna]

i get around 400-420 km per gas tank of about 53L fillup (12.7l/km) if i drive normally in the city...not sure if that is good or bad but it is about the same as my h22 prelude that i used to have before the msp

 

[tehturbo]

don't be surprised when your car is more effecient when you tune it, essentially that is what you wanted to do all along. You add mods to release power by taking stress of the engine, of course you're going to get better mileage, you are running cleaner and easier.