Results of ECU reset and other for feul economy

[Weborific]

OK, so I've reset my ECU in an attempt to get better gas mileage and my results seem positive. I used to get a maximum of 320 Km per tank from FULL to gas light, now I've got 360 Km. Here's what I did (thanks to all your posts!!) along with the ECU reset:

- inflate tires properly and use your own digital gauge. My gas station's gauge was off by 10 PSI!! It showed one tire at 33 PSI when in fact it was only 22.5 PSI on my digital gauge...

- Shave a couple of minutes off warmup idle on cold days

- Turn heater dial all the way CCW to "face" setting, this way the compressor isn't running.

Here's what's weird... I filled the gas tank and here's what I got:

- at 3/4 tank full mark: drove 120 Km total
- at 1/2 tank mark: drove 230 Km total
- at 1/4 tank full mark: drove 350 Km total
- at 360 Km, gas light went on

IS THIS NORMAL?? Needle is still just a touch under the 1/4 tank remaining mark...

 

[Kansei]

360km on the tank isn't really great fuel economy at all. You can take all your numbers and just tack "miles" on to the end and that's not even super duper gas mileage for a Protege5.

You're seriously getting as bad fuel economy as I am with my horribly rich running turbo setup and me driving the car really hard.

When were your spark plugs/wires last replaced? Is it an automatic? Something's really up to have gas mileage that bad... winter blend petrol won't make it that bad at all.

 

[Weborific]

Thanks for reply! Yeah, my mileage sucks. I replaced my spark plugs about 3 or 4 months ago and my wires about 8 months ago. I had trouble finding wires for the P5 here in Montreal (which is surprising to me) so I ordered 2 sets from Ebay, both where wrong for the P5. I FINALLY found a spot that had the wires in Montreal, but not thick, high performance ones. They look like the standard ones....

 

[redpr5]

my gas mileage kinda sucks. i just took the crossbars off the roof rack so i'll see how that helps. just had new front tires put on and gettin new rear tires this week so that will solve any tire problems. just did the spark plugs like 4 or 5 weeks ago, havent done wires yet. mines an automatic with a SRI (which i know doesnt help mileage) and i baby it everywhere. im lucky to get 320miles to a tank. i used to get over 340
btw kansei, sucks about your car man. right after you got it turboed too. get it runnin again soon.

 

[Weborific]

I originally replaced the spark plugs like 2 weeks after I bought the car March of last year. I bought NGK's (I THINK they were iridiums or something). I was getting AT MOST 460 Km before the gas light lit. Then, a few months ago, I had my brother-in-law (a mechanic) check my spark plugs (don't remember why) and I asked if they needed to be replaced. He said they didn't look too bad but (if I remember correctly) he mentioned that they didn't have much life left in them...and this was after a maximum of 7 months of use. He installed new NGK's and told me that they're COLD spark plugs. He told me they'd be better for winter, although after what info I've read on-line, this doesn't appear to be true. I've read a statement or 2 indicating that COLD plugs reduce gas mileage, but haven't found anything definitive....

 

[Weborific]

I'm having a really hard time finding performance wires for the P5. Can anyone suggest a site??

 

[Kansei]

You don't need thick high performance wires. The OEM wires or the wires NGK sells are good enough for anything. I had high performance wires (sparkco brand) that went bad on me, causing bad misfiring..

Do you remember what brand/model spark plugs? The NGK BFR5F-11 is the standard Protege5 plug, but you can run the NGK ZFR5F-11 as well, it seems to smooth things out a bit.

I'm really scratching my head here trying to think what else could be amiss causing such bas gas mileage. Are there any modifications to the vehicle? Even with the extensive modifications my engine had before I turboed the car, I still got fuel economy of 6.42 litres per 100km on the highway, and not that much worse driving around in the city.

 

[Kansei]

Oh that's it! If he went with a 6 heat range plug instead of a 5, that could cause it. With all my modifications (before being turbo of course), I still couldn't run the 6 heat range without the car's performance suffering.

I'd buy some NGK ZFR5F-11 plugs, they're very cheap (since they're copper) and slap them in and see how things go.

 

[Weborific]

No, I don't remember what brand of wires, I just wanted to replace the originals that the previous owner was still using. I swear, he didn't take care of her and I'm the one paying the price! There are no mods to the car what-so-ever. Thank you guys SOOO much for taking the time to help. I was hoping the above steps I took (listed above) would help me crack the 400 Km mark and the info would help others in the same situation... sorry. My last bet (I'm really wondering) is that tomorrow I'll fill-up at a different gas station. I topped-off about 17 litres from a different station this last time. I wonder if this is what has accounted for the 40 Km increase....

 

[Weborific]

Thanks for confirming this, Kansei!! OK, so (without me sounding too stupid here) where can I get these spark plugs? Are they special order or will anybody have them? Up until my last plug change, I had no idea there where different classes of plugs like COLD plugs...

 

[Weborific]

I just realized something I need help on. When I bought my spark wires, the box had only 2 wires in it. 1 long, 1 short. I understand that we have coil packs. But I just found P5 wires on a website and that kit comes with the same 2 wires I've got PLUS 2 connectors without an actual wire to them. Are these for the coil packs? If I remove the coil packs, is there something I can replace without replacing the entire coil pack?

 

[whitemp5seattle]

I think it's just something about Montreal that's giving you bad mileage. When I drove up to Montreal this weekend I got about 75 miles per quarter tank - 300 miles per tank. When I drove back down to CT I got my usual 100ish per quarter tank - almost 400 miles per tank. (dunno)

 

[i12drivemyMP5]

Thanks for confirming this, Kansei!! OK, so (without me sounding too stupid here) where can I get these spark plugs? Are they special order or will anybody have them? Up until my last plug change, I had no idea there where different classes of plugs like COLD plugs...

Sparkplug.com

 

[newprot5fan]

hey man,

you are getting about the same gas mileage I am.

Maybe it is the cold here in Canada during the winter (I am in NS). I have replaced my air filter, checked my tire pressure, about to put some V-power NGK spark plugs in, and soon cahnge the transmission fluid (manual). I have also run a bottle of the "fuel system cleaner" through the system this tank, so hopefully that might improve it a bit, but I hear you about the crappy mileage. I got my car used, and I don;t think there were any modifications done.

Are those numbers you have for mileage a mix of city/highway, or what?

 

[ctt 1982]

i usually get a consistent 550km per tank in the frigid cold wastelands of edmonton

edit: and i drive like a madman

 

[P-Funk!]

Key here -the ecu reset did nothing. The correct tire inflation and better operating technique account for the improvement.

 

[Kansei]

Thanks for confirming this, Kansei!! OK, so (without me sounding too stupid here) where can I get these spark plugs? Are they special order or will anybody have them? Up until my last plug change, I had no idea there where different classes of plugs like COLD plugs...

You should be able to get them at any auto parts store. They're a pretty standard plug.

 

[treybrad]

- Turn heater dial all the way CCW to "face" setting, this way the compressor isn't running.

Is this true? I don't mean to threadjack, but I've tried to search for this before, I know on my '02 it seems like the a/c compressor kicks on w/ the heater even when the light is off. Is that the way around it? Just keep it on the "face" setting instead of feet?

trey

 

[Kansei]

Yes, the a/c compressor kicks on even when the light is off. There's a how-to for disabling that around here somewhere, it involves some circuitboard soldering.

air conditioning won't decrease the gas mileage on these cars that much but it sure does suck the pep from them.

 

[JoshP5]

Interesting...I run on "face/feet" mode constantly and have been scratching my head as to why I'm getting 250 miles to the yellow light, even after plugs, filter, and seafoam. Maybe "face" mode will solve my fuel consumption problem, too...