Garbage gas mileage, 10mpg

Grn92LX · Sep 24, 2004

Lars, getting a tweecer or any of those expensive tuning devices isnt cost effective for me and I dont know and dont want to know how to use it. Some of them i'd need a lap top for as well which I dont have. My 'optimizer' is more than enough for now. I've tried a "real tune" and it didnt work. Yep, still hope the shop burns down Fwiw, I have gotten low 20's for mpg with h/c/i with a bit of hwy driving. I used to also get around 16 around town.

Im thinking of changing my 02's and coolant temp sensor. I know at the parts store bosch sells longer wire 02 sensors, but is there any place online that sells cheaper?

Michael Yount · Sep 24, 2004

Grn92 - remember, if the diagnostic codes aren't pointing to a problem with the ECT or the O2's, then replacing them, while it won't hurt anything, probably won't help anything either.

bgjohnson · Sep 24, 2004

also remember micheal a grounded out sensor is different then a disconnected one.

Grn92LX · Sep 26, 2004

It doesnt seem as if my mileage is improving. I got about 100 miles to the 1/2 tank with around town driving and some beating on it.

Another thing I remembered, I blew a head gasket a year and a half ago. Is it possible that since I know coolant got on the o2 sensor, that it weakened it? I remember puling my head off and watching antifreeze pour down my H pipe LOL. After I figure out my mileage on this tank if it doesn't improve im going to do new o2's and a new coolant temp sensor.

Where online can I get GOOD 02's for a good price with options for wire length? I'd like to get one with about a 15" harness. I dont want to cut/splice and I dont want extension harness.

5spd GT · Sep 26, 2004

Grn92LX said:
It doesnt seem as if my mileage is improving. I got about 100 miles to the 1/2 tank with around town driving and some beating on it.

Another thing I remembered, I blew a head gasket a year and a half ago. Is it possible that since I know coolant got on the o2 sensor, that it weakened it? I remember puling my head off and watching antifreeze pour down my H pipe LOL. After I figure out my mileage on this tank if it doesn't improve im going to do new o2's and a new coolant temp sensor.

Where online can I get GOOD 02's for a good price with options for wire length? I'd like to get one with about a 15" harness. I dont want to cut/splice and I dont want extension harness.

Hmm...the mileage looks familiar to mine...I bet the only way to get around it is a tune...

I really doubt the coolant "weakened" your o2 sensors...the coolant would flow along the inside of the h pipe...and the actual senseing piece of the 02 sensor is closer to the middle of H-pipe...

What is wrong with wire extensions? 50resto sells both the wire extensions and OEM Motorcraft 02 sensors...

Grn92LX · Sep 26, 2004

5spd GT said:
What is wrong with wire extensions? 50resto sells both the wire extensions and OEM Motorcraft 02 sensors...

I don't wanna spend $30 on top of new sensors. Parts store here sells bosch 02s and I remember him asking me what length I wanted, BUT I dont wanna spend $60 a piece, when I think i've seen them online for $40. I'll check that site 50resto though.

Have you ever done your gas mileage before? Keep in mind that with those 373's and the white 23T speedo gear, when you do your mileage, its actually less mpg since the 373/23T gear combo reads faster than your really going adding more miles. So for example, if your mileage comes out to about 13, its really like 12.

Grn92LX · Sep 26, 2004

This kit looks pretty good for $88. http://store.summitracing.com/partdetail.asp?part=FMS-M-12071-K302&N=110&view=257 I cant find o2 extension harnesses on summit, can someone find it for me

5spd GT · Sep 26, 2004

Grn92LX said:
I don't wanna spend $30 on top of new sensors. Parts store here sells bosch 02s and I remember him asking me what length I wanted, BUT I dont wanna spend $60 a piece, when I think i've seen them online for $40. I'll check that site 50resto though.

Have you ever done your gas mileage before? Keep in mind that with those 373's and the white 23T speedo gear, when you do your mileage, its actually less mpg since the 373/23T gear combo reads faster than your really going adding more miles. So for example, if your mileage comes out to about 13, its really like 12.

Yeah I knew about the mileage...I was working on a tank (but I'm doing the clutch install)...so I'm still waiting to finish it off...I might wait till after the clutch install to do a real tank...because my speedo gear is tore up bad...though it still worked (but bounced)...the internal gear looked good so I'm not worried...

Grn92LX · Sep 26, 2004

Another thing I just thought of is my car will run really cool especially at night. On an open road at night it'll run like 165*. I know the cars getting into closed loop, but could that be an issue as well running too cool in closed loop? I do have a few stats in my garage to use, im just too lazy right now. I will change it since winter is comming. It still gets up to a normal temp, but just at night on an open road its around 165*.

Michael Yount · Sep 26, 2004

Let's see - speedo gear is torn up, speedo's bouncing, and you're trying to estimate mileage off of that and the (notoriously inaccurate) fuel gauge. With all due respect, I don't think you really know what kind of gas mileage you're getting. I'd fix the speedo, check it for accuracy, and then actually check the gas mileage. Run a tank, then fill it to the top and divide the # of gallons it took to fill it into the miles you got on the tank. Estimating by miles per '1/2 tank' is no way to check mileage.

Grn92LX · Sep 26, 2004

Michael, your talking to 5spd, right? My speedo gear is brand new.

Michael Yount · Sep 26, 2004

Yup....although anyone reporting mileage problems/successes by the mileage/fuel gauge method is subject to the same post. As inaccurate as the oil pressure/coolant gauges/tach/speedo's are in the cars, you'd think folks wouldn't even dream of trusting the fuel gauge. Maybe it's me....

Grn92LX · Sep 26, 2004

What do you think about what I said above with my car running too cool at times?

5spd GT · Sep 26, 2004

Michael Yount said:
Let's see - speedo gear is torn up, speedo's bouncing, and you're trying to estimate mileage off of that and the (notoriously inaccurate) fuel gauge. With all due respect, I don't think you really know what kind of gas mileage you're getting. I'd fix the speedo, check it for accuracy, and then actually check the gas mileage. Run a tank, then fill it to the top and divide the # of gallons it took to fill it into the miles you got on the tank. Estimating by miles per '1/2 tank' is no way to check mileage.

Well lets see here... ...when I did my intial gas mileage (my speedo was fine)....guage is accurate because I checked how many gallons I put in the car and how many it didn't take when I put a "new tank" in...so there goes your speedo problem and my "messed up fuel guage"...your right...I'm going to wait till I get the new speedo gear in...and when I said the speedo gear is messed up currently...it only bounces up to 20mph...and is steady at 60...

5spd GT · Sep 26, 2004

Grn92LX said:
What do you think about what I said above with my car running too cool at times?

So it runs cooler at night?

I know my car "supposedly" runs hotter at night...but that is only because when I turn on my lights (which could be your "night" problem)...that the guage reads almost another bar hotter (on stock guage)...

There is no real difference to a car in temperature by sensing that it is day or night (as you know obviously...)...but I bet it is electrical (headlights)...and yours does the opposite...

Are you getting your readings off a stock guage or an aftermarket guage...

Grn92LX · Sep 26, 2004

David, I run ALL autometer gauges. Car runs cooler at night because its cooler out Your gauges reading hotter at night with the lights on is a ground issue. I run autometer fuel pressure, oil pressure, coolant temp, vacuum and shift light

Both my stock and autometers are hooked up and tell me the same thing, car runs cooler at night.

FastDriver · Sep 26, 2004

Grn92LX said:
Well, my gas mileage blows. My speedometer hasn't worked in about a year but it works now so I checked my gas mileage last night and got 10mpg. Thats with around town and highway driving. I guess i'll give the car a code test and see if any sensors come up. I kinda think the problem is since i'm running a 24lb pro m 80mm mass air with 30lb injectors and a pro m remote optimizer that the 'tune' might be off. Im thinking of buying a 30lb mass air. I remember my car used to get around 16mpg with mixed driving and beating on it. My O2 sesnors are about 4 years old.

One quick thing about the O2 sensors, does it matter which harness they get plugged into? Is there a left and a right for them or it doesnt matter?

This is a simple fix... take the crap heads you've got off, and replace with AFRs...boom instant 22mpg...

Grn92LX · Sep 26, 2004

Chris, I always knew you were a homosexual, but now i'm once again re-asured that you are

5spd GT · Sep 26, 2004

Grn92LX said:
David, I run ALL autometer gauges. Car runs cooler at night because its cooler out Your gauges reading hotter at night with the lights on is a ground issue. I run autometer fuel pressure, oil pressure, coolant temp, vacuum and shift light

Both my stock and autometers are hooked up and tell me the same thing, car runs cooler at night.

Yeah I know in actuality that the car runs cooler during the night or in the morning (like mine does)...but I was just curious if yours was doing the same thing as mine...except opposite...

FastDriver · Sep 26, 2004

Grn92LX said:
Michael, another example I forgot to mention- My friend has an afr 165/rpm/FTI combo. He had 24# injectors and needed 55psi of fuel pressure to get the a/f nice. With his car all tuned he did run 12.40 @ 110.xx on et streets.
Mike

Make that 2 of your friends, bud. Remember my car ran about the same, and got 110 mph, but coughed and sputtered at 40psi with 24 lb injectors. At 55psi, they worked fine, though the AF could have been flatter.

You know what TFS stands for right?......Too ****ing slow

Garbage gas mileage, 10mpg

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