Any suggestions on how to improve my gas mileage? Last summer i was getting 18 to 19 mpg. Now I average 14 to 15. Nothing has changed externally that should cause this (i.e. bigger tires, grill guard) I've changed the oil regularly, I just changed the fuel filter, air filter, spark-plugs, wires, rotor and cap. My tire pressure is good. I've tried STP fuel injector cleaner from Autozone (they said it is guaranteed to increase the miles.. Nope!) They sold me on this stuff called Lucus fuel injector cleaner, don't know if it's worth trying or not... I don't notice a huge difference if i baby it while driving. It sucks the same amount of gas.
Any suggestions on what else i could do to get back to 18 19 mpg?How to improve gas mileage on my 2001 Nissan Xterra 4x4 V6?
Robert M mention cleaning IAC, what does IAC has anything to do with fuel economy?
IAC stands for Idle Air Control valve or solenoid. Its main purpose is regulate engine idle speed but absolutely has nothing to do with highway driving and fuel economy period.
Now for engine oil, Nissan uses regular engine oil since day one, I mean showroom fresh, the day someone buy their vehicle and drives off.
You were getting 18 -19 MPG last year, so what does oil has anything to do with sudden big MPG loss?
My suggestion is to take your vehicle to experience technician and explain him or her about your concern.
Yes, you may not like the idea but please keep reading.
Let them diagnosis your vehicle via scanner, there are few possibilities that can easily cause poor fuel economy.
1... Lazy oxygen sensor reading. In normal condition, oxygen sensors will fluctuate between .10 volts to .90 volts rapidly. Lazy oxygen sensor will reads too slow, this can easily kills your mpg.
2... Semi clogged Catalytic converter. Yes, you read it correctly, semi clogged converter, which can slowly restricted your exhaust system. Your motor cannot breathe freely like it used to be. It can be diagnosis on scanner by reading cat monitors [ another name for that is rear oxygen sensors] and comparing readings between front oxygen sensors and rear oxygen sensors.
3... Crankshaft sensor and camshaft sensor, once again, fluctuate readings can give computer false readings.
4...Barometric sensor and MAF sensor....again experience techs will know the differences.
You may say this, %26quot;My Check Engine Light%26quot; isn't on and my sensors are in good working order, unfortunately, that is incorrect. If your sensors falls within certain parameter, the computer will not throw %26quot;Check Engine Light %26quot; on.
Only experience techs will know what is going on by monitor various sensors via scanner. They may find something isn't kosher.
Example...
Lazy oxygen sensor, sometimes they read between .6 volts to .9 volts instead of .1 to .9 volts.
Technician will figure out why your oxygen sensor stays fluctuating on high side, technician will check other sources like vacuum leaks, fuel pump pressure, timing and other stuff.
If everything checks out ok, then it is just lazy oxygen sensor?viola..there goes your mpg.
One last thing, stop using too much fuel injector cleaners, you'll do more harm than good.How to improve gas mileage on my 2001 Nissan Xterra 4x4 V6?
you can bump mileage up by putting a good intake and/or exhaust system on it. if your driving habits are the same and nothing's changed on the car, something doesn't sound right about the mileage dropping by 5mpg in a year. i would have a mechanic check it and maybe do a full tune-up on it.How to improve gas mileage on my 2001 Nissan Xterra 4x4 V6?
Maybe the gear lube in the differentials/transfer case/ transmission.Are any of the brakes hanging up? E-brake on just alittle?Check the compression...worn cylinders? 4wheel alignment? There alot of variables that could effect MPG. good luck....added thought..plugged cat converter? Muffler?collapased pipe in the double wall section of the exhaust?How to improve gas mileage on my 2001 Nissan Xterra 4x4 V6?
First of all, locate remove and clean your IDLE AIR CONTROL VALVE!! This will make a BIG difference. Next, de-sludge your engine and swear off regular oils FOREVER!!! Use Mobil One, or ELF oil that meets Nissan specifications. This will automatically reduce friction and improve MPG's. Also, install a set of Nippondenso Twin Tip spark plugs, or Bosch FUsion if you can't find the other. They will also improve power and fuel mileage. Good Luck! Hopefully, you were smart enough to use ONLY OEM ignition parts. WIres were a waste of money, totally. They should last the lifetime of your car. 2001 is NOT very old. Spark plug wires from factory are infinitely better than aftermarket replacements. Trust me!! Good Luck!!
