RylAssassin

WTF my car is now getting like 10.5 miles to the gallon, thats what i worked it out to.
What do you guys recomend on checking for when getting low gas milage. I have recently upgraded my exaust and air intake system. I have the HKS for the intake and the AFM is in stock postion. Ive read that perhaps the AFM should be rotated 180 degrees when changing to a aftermarket system but i dont know if thats the case with my HKS.
For the exaust i have a straight pipe to a single N1 exaust.
Whats wierd though that i noticed the decrease in gas milage recently and ive had the intake and exaust in now for like more than a month
PLEASE HELP!

RylAssassin

oh yeah by the way i mostly drive on the highway between 70 and 80 mph and im still getting extremly crappy gas milage

emagdnim

I get about 11 MPG and my FC's stock, dunno what to tell you, I think it's rotary nature.

The Ace

I know that Mazda claims a totally incorrect 19-25mpg for the '89-'91 TII, but thats only if you are brain-dead, or just plain dead

If you actually have blood in your veins, gas mileage for the TII is around 15-20mpg (city-highway), and if you just drive it like it should be driven , then 10-15 is not unheard of (I know, because I have that mileage )

Dont expect good gas mileage from a turbo rotary.....

RylAssassin

THAT CANT BE! I did a search and i saw that a lot of ppl were reporting like 16mpg at the lowest! and the average seemed to be like 20-25 mpg all city driving of corse. I mean wtf, i love my FC but this cant go on like this im already poor i cant afford this kind of gas milage somthing HAS to be worng with it to be only getting 10.5 mpg

RylAssassin

Thanks ACE you are a god to me, but listen i dont have a turbo i have a good ol N/A s4 yet more proof that this 10.5 mpg is bs
Theres gotto somthin wrong with my car i need to know what to check to see if there somthing worng with the engine. Keep in mind i have no cats, an aftermarket filter, and a non turbo so i must get more than 10.5

The Ace

Hey, I can get something like 9mpg just driving -almost- normally, with the occasional redline or "road race". I'm also located in Greece, where the 96 Oct costs around 0.8EUR per liter, so we have something like 3 times the cost of the US gas. Do you see me complaining ?

actually I did, but that was a long time ago

You can have 25mpg with a TII, but you have to drive in 5th going 120-130kph, and pressing the gas pedal with a feather

RylAssassin

Ace i have an N/A s4

RXSpyder

My S5 Vert gets about 10-20 MPG depending how i drive it. And 20 bucks doesnt even fill my tank up with 89 octance.

Evil Aviator

You should get 17-21mpg with a good engine. How are you measuring your fuel consumption?

Do NOT rotate your AFM!

Some things which cause bad fuel economy:
1) Your driving habits
2) Engine not tuned (spark plugs & wires, timing, etc.)
3) Thick or sludged engine oil
4) Bad ECU or sensors (O2 sensor, temp sensor, AFM, etc.)
5) Fuel leaks (injectors, pulsation dampers, etc.)
6) Bad rotor seals - how is your compression?
7) Increased drag from a bad water pump, air pump, AC compressor, etc.

fuzzi

Check your o2 sensor ...Also put in some injector cleaner in your gas tank two of my buddies did that... and the one with the turbo II got 100km better on a tank of gas.. and they other guy now gets almost 800km just under on his toyota camry.... try it

Grizzly

OK,

How much is a gallon of fuel there?

I live in the UK where its between 80 and 90p a liter what about £4 a gallon ($6) and i drive a half bridge Turbo? (i am always poor)

The Ace

You kept telling me, and I kept not seeing it.....

....man, I got to get my **** together

You are right of course, 10mpg for a N/A is terrible gas mileage.
If you are indeed doing a lot of highway miles, then O2 sensor plays a major role. Check it out, see if its OK. Can you borrow an AF meter and see if you are running always rich ?

RylAssassin

Thanks guys so far for all the info
Ace i have my 02 sensor attached to underneath with some hose clamps, I have no cats this is why im doing this. Should i remove it and create a blocking plate or somthing? You think this could be the cause for my poor gas milage?

The Ace

eeerrrrr, I didnt quite get what you said just now: is the O2 sensor in your exhaust or not ? If it is, then having or not having cats does not play any role (other than emissions of course ). O2 sensor should be telling the ECU the A/F ratio, so that the ECU can adjust the injector timing, so that it can achieve stichoiometric ratio (trust me, I'm greek, this is how its spelled )

If you remove it, a) you'll cause the ECU to throw an error code, and b) you'll probably run at "failsafe mode", which is shitload rich !!!! Make sure you are not running like that already. Better check the ECU for error codes, and check the voltage of the O2 sensor.

In any case, only way to tell is an A/F meter....

Sonic

I've only tried once so far in the 2 months I've had the car. I got 17mpg.

It is a TII w/ clean injectors by the way.

christi

I get about 17 in city and 20 on highway. But it also depends on the speed i'm going. If you're in high RPMs, and dumping the throttle at high speeds, of course you're gonna burn alot more gas, and get less gas mileage.

At first, my fuel pump wasn't in good enough shape (that I thought, because of the poor gas mileage)- put in another one from an 88 as well at Brian Smith's house. I am not sure if it made the difference though. They told me I had nothing wrong with the pump, just that I am/was dumping the throttle way too much....

But then again, I'm not sure with the mods you have.. I just know what I stated above... =/

TomR-90

make sure your plugs are in correctly. T is not top, L is not lower.

MechE00

They must spell things differently in Greece..
http://www.dictionary.com/search?q=stoichiometric



Yeah, I'd suspect your O2 sensor's feeding your ECU bad info.. you can't be getting very good performance with that kind of inefficiency. .

Everything else on the car works fine except you're just getting horrible gas mileage?? Smooth idle, no stumbling, etc.?