Burning Rich

[laksman91]

would it be possible for my engine to be burning rich? I find it extremely hard to reach 400km/tank flat. This is with a calm driving style. I usually rev to about 3200 maximum. The thing is its all city driving.

On the side note: Dont ask why, but a few months ago i filled up the tank with 94Octane (2x in a row) would that have thrown off my ratio settings (?)

So what can i do about this problem?

[mazdas3sporte]

yes

[laksman91]

So what can i do.

[dentinger]

im in the same boat...
i cant get better than 450/tank
however, i have an intake, and full exhaust, but i dont race the car too often, and i shift 1st at 3000, 2nd at 3000, and usualy 3rd, 4th around 2,000-2,500.

[laksman91]

im at 370km right now and the light turned on :o
I got a mazdaspeed CBE installed

[dentinger]

shit.
thats really bad.
my record was around 300, but that was back when i first got the car, and was learning to drive stick....

[laksman91]

is there a way to reset "ratios/timings"?

[rcd001]

If you disconnect the battery for 5 minutes the PC will reset. Maybe this will help. I've been running high octane for some time. I stay away from sunaco, because even though the car is more responsive with 94% octane, the gas milage is poor. Try Esso premium or Petro Canada.

Maybe it's the high ethenol content in sunaco gas.

[laksman91]

how do you disconnect the battery terminal do you have to screw it off? i got the cover off atleast

[dentinger]

haha

10 mm wrench, if i remember correctly. it might be an 8mm.
and jsut turn in counter clockwise until the terminal is loose, and then pull it off.

note: sparks when reattaching the terminal is normal.

[x_o_k_x]

if that doesnt help.. I noticed myself that it takes time to adjust for a proper fuel economy. So let say if you got 400 out of a tank driving calm, you need to fill up at least twice more to get best results. Its just the way it works.
I remember when I drove pure 100% city and my milage was like 550 after fill up. So next time I would fill up it would take the whole tank to adjust to normal driving conditions..and will improve your milage for an extra 100km

[mazda lover]

If you disconnect the battery for 5 minutes the PC will reset. Maybe this will help. I've been running high octane for some time. I stay away from sunaco, because even though the car is more responsive with 94% octane, the gas milage is poor. Try Esso premium or Petro Canada.

Maybe it's the high ethenol content in sunaco gas.

NO need to run high octane gas, just wasting your money. Why are you using high octane? Manual says to use regular...I am sure this has been talked about before..

[kaval]

Only reason to use higher octane is if you are boosted, tuned to run on it, or compression ratio is high. Other than that, if the manual says regular, use it!

Have you had your car tuned to match the mods?

Are you up to date on your maintenance?

[theurgy]

If you use any Ethanol you will lose gas mileage. It's why i no longer tank up with Sunoco Ultra 94 as it uses 10% Ethanol in order to up the octane level.
Ethanol as an additive is stupid really.. I mean it's there so it cleans up the air and for corn companies to profit, however it burns much faster than regular petrol.
With regards to octane rating.. if you are driving a regular Mazda3, there is absolutely no reason to run on any higher octane fuel as your timing and tuning is not set for it, so really you're just paying the extra with no benefit.
Same goes for you Speed3 guys who are stock (not using the Cobb or CP-e tunes).. 94 octane is useless. I usually buy the Ultramar Premium (91 octane) no ethanol in non-urban areas and it's 3 cents cheaper on Thursdays.

Also the best way to calculate your fuel economy as I've found the average on the computer is inaccurate is to do the following.

Go to your regular gas station and pick a pump.
Fill all the way up until the pump clicks.
Reset your trip meter.
Then drive until your car is near empty.
Go back to the same pump and station and fill up until it clicks again.
Now take note of the value on your trip, and the litres on the pump.
This will give you a km's / L value.
Multiply the KM by 100 and then divide by the number of Liters.. and there you have you L/100KM rating.

[laksman91]

Well I only used the 94 octane twice in a row. No longer do it. But I fear it has effected my fuel economy

[laksman91]

for kavals point I haven't tuned it for my new catback but what kind of tuning would I require. And also I am up to date with the maintenance

[condor888000]

K, disconnect your battery, wait about 5 minutes then reattach it. Fire up the car and let it idle for a couple minutes. Fill up on 87 and see how long it lasts.

There is no easy tuning for this car.

[rcd001]

We all run the fuel we use for different reasons; sometimes it may be a waste.

I run high test because the engine timing is advanced, I think it is better for the environment and I think it will keep the engine cleaner.

Even before I had the timing advanced I have always done this practice. Is it a waste of money, perhaps, but it makes me feel better.

Ethanol based gas has effected me on al 3 cars. My honda accord, imprezza and 3. When I travel to the US I find I have to high test because the regular gas makes the engine idle rough on these cars.

I stay away from Citco because I had to clean my injectors when I came back to Canada.

Just my two cents.

[FLIPDADY]

What's your driving style like? City or highway? Do you drive the car hard? Is regular maintenance done on your car?

[Zoom Zoom Boy]

Same goes for you Speed3 guys who are stock (not using the Cobb or CP-e tunes).. 94 octane is useless.

Can you elaborate on why you believe the 94 octane is "useless" in a stock MS3? Not questioning you to be confrontational, I am just really curious as to the reasoning and maybe I will learn something. The MS3 compression ratio is quite high, even for a turbo engine due to the direct injection and on the surface at least, I would have belived that 94 octane would actually be somewhat beneficial to this engine, COBB tuned or not. I would be more than happy to understand if this is indeed not the case and have an explanation as to why.

[theurgy]

Well... it's like this. The gas companies like to make you believe that high octane gas is cleaner and more efficient, when in reality an octane rating is there solely as a guideline to tell you that it is less at risk of pre-ignition.
A regular engine is tuned and timed to run, expecting that the gas will not ignite before it's supposed to.
When you get into forced air induction, you start getting into higher risk of pre-ignition as you have much more volume of air in the cylinder.. so to compensate you use a higher octane gas, which reduces that risk of pre-ignition.
However.. just as much as running 91 octane in an 87 octane tuned engine... is useless as you're paying for a product that will do exactly the same thing in the end.
Running 94 octane in a 91 octane vehicle will do the exact same thing.
My main gripe is that most 94 octane gas in 10% ethanol (Sunoco Ultra 94) and I've already explained my views on 94 octane.
Now getting gas that is unclean as opposed to getting what is perceived as a regular octane gas is a different matter. Some gas retailers use very dirty gas. They cycle through 87 octane gas quick as it's the cheapest and those pumps and lines are used and abused.
89 octane is just 87 octane with ethanol (like Macewan).
The 91 octane is more strictly regulated because of it's applications (higher compression, engines.) This is not to say you may not get bad gas with High test.. it's just a lower risk.
That's just my views.

[rcd001]

My driving style is not really relevant because I drive my 3 maybe 2-3 days per month.

On straight hwy at an average speed of 138km/h I can do 600-625 Km range. I prefer to fill at 600 so I have room just in case I can't find a service exit.

On mixed (city 80% and hwy 20%) I can do 500 - 550.

So in regards to high test being cleaner gas, for a small cost each fill up you get better peice of mind. If you drive a lot I can see it not being worth the cost, but if you are like me and drive less then 20K per year, it is not really going to affect my bottom line.

I have always been more comfortable paying a little extra for peice of mind. Like insurance, you don't really need it (except for legal issues) but in case of an accident the $200 per month is nothing compared to the $10K= for the repair cost. The $200 per month is a constant expence so you can easilly budget for.

[laksman91]

What's your driving style like? City or highway? Do you drive the car hard? Is regular maintenance done on your car?

Driving style relatively calm (up to 3200RPM) with a few spirited moments in a tank.
100% City
I wouldnt say I drive the car hard.
Regular maintenance is done.

[laksman91]

okay so resetting the battery did not help, do I have to wait a few tanks for this?

[chinsterr]

the 3 has terrible gas mileage .... its not your driving style