So im out of ideas on my MPG. (Hate to make this thread)

[ltsnotme]

I have no idea how to do this . . . there is absolutely no power band under 2k. I mean, I follow people that drive like this on the way to work everyday, but I don't think I could live with myself if I drove like them

 

Haha, I know. It's definitely not an everyday solution. I've done it for 1 tank, and it was pretty depressing. Keeping it under 2.6k is more realistic though, since this is closer to when my auto trans. usually upshifts, and it still adds about 1 mpg.

Edited January 24, 2013 by ltsnotme

[dynomax]

Based on what you've done so far(i.e. new plugs, wires, O2 sensors are good) my suggestion would be:

 

1. Check that exhaust manifold leak because if the O2 sensors read lean mixture (due to the leak) the computer will dump more fuel

2. Check your air-filter, replace it, they're cheap

3. Get yourself the 3M complete fuel system cleaning "kit" that comes in a box with three bottles. Run the fuel tank bottle with half tank of gas.

 

If you have any luck, let me know. I am getting 10-11mpg city in thte winter, 12 in the summer, and 14mpg highway winter and 16 summer. 2004 model 3.5L. i have just accepted the fact that these things are pathetic on fuel... and awaiting my next upgrade. Friend of mine with a 2010 f150 5.4L gets 14 US mpg around town and 19 highway... maybe i need a ford... oh wait, i dont think i like domestic that much

 

my 2012 4.8L chev work-owned pickup gets about the same mpg, little better on highway.

 

air filters dont make a hill of beans difference unless they're caked with mud!

Edited January 24, 2013 by dynomax

[MY1PATH]

I've noticed that if I keep the revs under 2k while accelerating, I gain about 1.5-2 extra mpg's in the city. This does make for some pretty boring driving though.

Funny you say that because my vaccum gauge tells me that vaccum drops more easily under 2.5k.

I did a drive up to the mountain and back on monday and over a controlled (filled up before and after) 100.2 miles I used 5 gallons; 20.4MPG. I watced the vacuum gauge to try and keep it in the green, My foot was very gentle on the pedal but I was shifting at 4.5-5k to make the next gear run at 3k.

This is actually how I normally shift but my rev matching was more gentle and my acceleration was slower.

 

Normally I think her truck gets arround 18.5 going up and down the mountain.

 

I understand shifting early and limiting your RPM but you might also try shifting in your torque band an limiting your air intake(fuel too) by being gentle on the throttle.

 

maybe you have a lemon? My 94 was a lemon, I'm glad its gone.

[drewp29]

Friend of mine with a 2010 f150 5.4L gets 14 US mpg around town and 19 highway... maybe i need a ford... oh wait, i dont think i like domestic that much

 

Funny, the ONLY domestic I would consider buying these days is a Ford since they didn't take bail-out money. I figure if I owned a small business and ran it into the ground with poor business practices / money management then my business should fail. The government wouldn't offer to bail me out to keep my business afloat, so why should it be any different for a large company.

 

Just my opinion

[MY1PATH]

Funny, the ONLY domestic I would consider buying these days is a Ford since they didn't take bail-out money. I figure if I owned a small business and ran it into the ground with poor business practices / money management then my business should fail. The government wouldn't offer to bail me out to keep my business afloat, so why should it be any different for a large company.

 

Just my opinion

AGREED but NEW vehicles make up all too much of our nations economy. Why does everything have to be so NEW. This going green @!*%, NEW means making that car cost more to the environment than driving an old one for 20 years would. If Auto companies crashed or stopped releasing NEW cars all the time, that money in the the economy would not go a way, instead it would go to mechanics and auto parts and all the necessary things to keep older cars running.

[drewp29]

AGREED but NEW vehicles make up all too much of our nations economy. Why does everything have to be so NEW. This going green @!*%, NEW means making that car cost more to the environment than driving an old one for 20 years would. If Auto companies crashed or stopped releasing NEW cars all the time, that money in the the economy would not go a way, instead it would go to mechanics and auto parts and all the necessary things to keep older cars running.

 

I totally agree! Don't get me wrong, I'd love to drive a hybrid or all-electric as a DD just to save money on the cost of fuel. However, if you look at the initial cost increase for the technology your return on investment is longer than the vast majority of people keep their cars before selling them. Even second hand you end up paying a premium and unless you plan on keeping it for 5+ years you won't realize much monetary gain overall. My parent's just recently bought a new Jeep and are probably looking at buying another new car soon, but they will have both of them for the rest of their lives, so it makes sense now. They have NEVER purchased a NEW vehicle as long as I have been alive.

[Howie]

Preaching to the choir on this forum. We all drive old vehicles!

[MY1PATH]

Preaching to the choir on this forum. We all drive old vehicles!

2001 isn't old, it just a used adolecent!

lol haha

[ltsnotme]

Funny you say that because my vaccum gauge tells me that vaccum drops more easily under 2.5k.

I did a drive up to the mountain and back on monday and over a controlled (filled up before and after) 100.2 miles I used 5 gallons; 20.4MPG. I watced the vacuum gauge to try and keep it in the green, My foot was very gentle on the pedal but I was shifting at 4.5-5k to make the next gear run at 3k.

This is actually how I normally shift but my rev matching was more gentle and my acceleration was slower.

 

Normally I think her truck gets arround 18.5 going up and down the mountain.

 

I understand shifting early and limiting your RPM but you might also try shifting in your torque band an limiting your air intake(fuel too) by being gentle on the throttle.

 

maybe you have a lemon? My 94 was a lemon, I'm glad its gone.

 

Not sure I understand...how would that make it a lemon?

[MY1PATH]

Not sure I understand...how would that make it a lemon?

Bad fuel economy...somethings wrong that cannot be traced down...and it gets expensive...

Our 94 had all kinds of issues, expensive ones, it was more expensive to keep it than it was to just buy a 93

[ferrariowner123]

Wait, i just had a thought, wouldn't my CEL be tripped if if saw my O2's were reading weird?

 

Or shouldn't i be able to see jumps in readings though a diagnostic tool? I had the O2's checked when i took it in after my knock sensor replacement, and they said the O2's were fine, but they didn't specify if they car was running, unless the only way to know is if the car is running.

 

Is there a way i can confirm the O2's are getting bad readings by way a of blown/ crack manifold? i just really want to confirm all of this before i spend alot on new manifolds.

 

let me know what you think guys.

 

-Kyle

[shoesandsocks]

get some seafoam spray the one wit hte bendy straw (best way i can describe it) and spray it into your intake manifold if it comes out of the engine bay namely the headers u have a leak if it all comes out the exhaust in the back your good thats how i unintentionaly found i had a mani crack in my hardbody.

 

and on your cel light

 

your truck might not throw a code for the before cats 02 for it reading lean especially if your cats are good because it doing its job modulating the car to keep it within acceptable range ie first o2 has reading that helps adjust air and fuel exhaust goes through cats second 02 says this is acceptable range from what first guy says and no code is thrown by the ecu. even though its eating your gas to do it its working properly

Edited January 25, 2013 by shoesandsocks

[ltsnotme]

Bad fuel economy...somethings wrong that cannot be traced down...and it gets expensive...

Our 94 had all kinds of issues, expensive ones, it was more expensive to keep it than it was to just buy a 93

 

Oh, well I get about 16 mpgs combined, which seems to be the average for my year. I think you were probably addressing the OP at that point, and I thought you meant me.

[dynomax]

your truck might not throw a code for the before cats 02 for it reading lean especially if your cats are good because it doing its job modulating the car to keep it within acceptable range ie first o2 has reading that helps adjust air and fuel exhaust goes through cats second 02 says this is acceptable range from what first guy says and no code is thrown by the ecu. even though its eating your gas to do it its working properly

 

I am interested in this, not interested in the placement of them, or changing them, if they're not bad! How can you check them? I am at least 2mpg to 6mpg lower than reports i'm hearing here (in summer time -- I do realize my winter mpg will be way lower). No CEL here.

[90seven]

Have you tried unplugging some sensors? Could probably have a bad sensor. Anyone ever heard of sensors NOT tripping the SES/CEL?

 

I'm not sure of the piece but I'll take a pic of the location of my leak. It was under the hood, so the smell of gasoline was significant which made it easy to pinpoint.

[MY1PATH]

Oh, well I get about 16 mpgs combined, which seems to be the average for my year. I think you were probably addressing the OP at that point, and I thought you meant me.

yes, I was addressing the OP.

[Trogdor636]

Anyone ever heard of sensors NOT tripping the SES/CEL?

I'm pretty sure Alkorahil (our resident Nissan parts guy) has said more than a few times a bad O2 sensor won't necessarily trip your CEL.

[MY1PATH]

I'm pretty sure Alkorahil (our resident Nissan parts guy) has said more than a few times a bad O2 sensor won't necessarily trip your CEL.

Yep. These ECU's don't trip for much. I've had bad O2, Bad MAF, leaking injectors to name a few things and didn't get codes for any.

Edited January 27, 2013 by MY1PATH

[devonianwalk]

Yep. These ECU's don't trip for much. I've had bad O2, Bad MAF, leaking injectors to name a few things and didn't get codes for any.

 

Good to know. I'm quietly questioning my current MPG's. Shhh!

[fixinto]

get some seafoam spray the one wit hte bendy straw (best way i can describe it) and spray it into your intake manifold if it comes out of the engine bay namely the headers u have a leak if it all comes out the exhaust in the back your good thats how i unintentionaly found i had a mani crack in my hardbody.

 

and on your cel light

 

your truck might not throw a code for the before cats 02 for it reading lean especially if your cats are good because it doing its job modulating the car to keep it within acceptable range ie first o2 has reading that helps adjust air and fuel exhaust goes through cats second 02 says this is acceptable range from what first guy says and no code is thrown by the ecu. even though its eating your gas to do it its working properly

^^ same thing bout the sea foam found it after my valve cover gasket replacement and tb clean. "think i posted that somewhere" dont really remember

[Alkorahil]

I'm pretty sure Alkorahil (our resident Nissan parts guy) has said more than a few times a bad O2 sensor won't necessarily trip your CEL.

 

 

Yes that is correct!

It can be 'stuck' sending a constant voltage (instead of fluctuating voltage) to the ECU that is within the nominal readings the ECU is looking for. Thus the ECU wont trip the CEL.

[fixinto]

i would address the exhaust leak, if its under hood its probably pre cat. After that if nothing improved i would throw a couple of sensor 1 O2's at it, they r pretty cheap and it cant hurt. However if you want to test them, i believe you can back probe them after they are warm and watch for voltage changes when you rev the engine say between idle and 3500rpm. Just an idea. even with it being winter I'm rockin the 16mpg average. but i know there are a couple of things i can do to possibly improve on that. just waiting on warmer happy times.

 

 

PS i have heard of people putting their O2 sensor in a vise and using a propane torch to heat them up while measuring the voltage to ground. if you pull the heat away they r supposed to react almost instantly. If your o2's are getting slow it will cause crappy crap crap to happen too.

Edited January 29, 2013 by fixinto

[dynomax]

i would address the exhaust leak, if its under hood its probably pre cat. After that if nothing improved i would throw a couple of sensor 1 O2's at it, they r pretty cheap and it cant hurt. However if you want to test them, i believe you can back probe them after they are warm and watch for voltage changes when you rev the engine say between idle and 3500rpm. Just an idea. even with it being winter I'm rockin the 16mpg average. but i know there are a couple of things i can do to possibly improve on that. just waiting on warmer happy times.

 

 

PS i have heard of people putting their O2 sensor in a vise and using a propane torch to heat them up while measuring the voltage to ground. if you pull the heat away they r supposed to react almost instantly. If your o2's are getting slow it will cause crappy crap crap to happen too.

 

Any tips on replacing these? My arms are only 2 and a half feet long, and I have one elbow...

 

I've kindda been ignoring them, hoping the pathy just gets bad MPG... hahaa..

 

No really,what kind of sensor is best to replace them with, and how do you get em.

[adamzan]

I'd use a Bosch o2. They make the nissan ones.

[MY1PATH]

I'd use a Bosch o2. They make the nissan ones.

Bosch and NTK o2 are the best ones you can buy. I think they also cost the most...