'96 Pathfinder - 16.9 mpg - Pathetic!

[Albin]

I have a '96 Pathfinder, 2nd owner; bought just about a year ago. Original owner had not driven it in over a year due to dementia; his daughter sold me the vehicle.

Since I bought it, I've:

- Had the timing belt replaced; it should be good for at least 5 years now - reputable Nissan shop (RNS)
- Water pump replaced, same time as the TB (RNS)
- New air filter (Fram, I think)
- Changed the oil and filter twice now (Wix filter)
- Had it tuned up with new spark plugs, SP wires and points etc. ETA: they also changed out the fuel filter. (RNS)
- Did one transmission fluid swap (about 3.5 qts out of 9)

Gas mileage is about 16.9 mpg. Most travel is TN rural 2 lane roads; very little stop and go traffic - usually towns with 2-3 traffic lights.

Next steps:

- Mass air flow sensor - clean and/or replace
- O2 sensor - clean and/or replace

Any other ecoomendations? I can't believe that a 3l gas engine can't make better gas mileage.

Thanks for any comments, suggestions and help.

 

[michaelluscher]

EPA rating was 15 city/19 highway
2/4WD?
A/C on?

My experiences with several VG33 V6s yielded similar mileage
Clean the MAF, check for vacuum leaks, fuel filter?
Anyone put a timing light on it lately? (If it's had a distributor, which it probably has had at least 1)

Scan for codes, thermostat making it fully warm up?
Check TPS adjustment, pull the vacuum hose off the FPR, make sure it's not leaking fuel

It's been a minute since I dug deep into my Villager, a Pathfinder, or an old Maxima

 

[mcm0455]

Still better than a $1000 car payment…

 

[Zee09]

Dump the WIX oil filter...

 

[SC Maintenance]

Sounds about right for a 4000lb brick with a VQ engine. My even more modern Xterra gets about same.

2wd or 4wd?

Who is driving it. VQ mileage is not at all forgiving for even a mildly aggressive skinny pedal.

I would log your long term fuel trims before you fire the parts canon.

Also MAF cleaned and logged as already mentioned. Should be around 3.5 at idle.

Pull a plug and have a look - one by the firewall, there always the worst for some reason.

I promise you won't get much better than 18-19 unless you push it down a hill.

 

[Mainia]

2 bottles of Redline S-1 injector cleaner to 1 full gas tank.

 

[Nessism1]

Sounds about right for a 4000lb brick with a VQ engine. My even more modern Xterra gets about same.

2wd or 4wd?

Who is driving it. VQ mileage is not at all forgiving for even a mildly aggressive skinny pedal.

I would log your long term fuel trims before you fire the parts canon.

Also MAF cleaned and logged as already mentioned. Should be around 3.5 at idle.

Pull a plug and have a look - one by the firewall, there always the worst for some reason.

I promise you won't get much better than 18-19 unless you push it down a hill.

As mentioned by @michaelluscher , it's got a VG33 engine. Not VQ.

 

[cheech279]

A bottle of Techron in the gas tank and a new PCV valve.

 

[Pablo]

On a good day my 2019 Tacoma gets 19mpg. On a downhill for 10 miles I might break 20 mph. It is regeared to 4.88. Maybe someone swapped gears?

Or just have @Patman drive. Miracle Miles per Gallon that guy

 

[SC Maintenance]

As mentioned by @michaelluscher , it's got a VG33 engine. Not VQ.

Even worse. 2 valves.

 

[Towncivilian]

Swap out the differential(s) fluid for 75W-90; factory spec is 80W-90 so synthetic might help a fraction. If it's 4WD, swap out the transfer case fluid as well.

The driveshaft(s) should have a grease fitting. Make sure that these get greased periodically. Not necessarily an MPG improvement but something that could be easily missed.

Second the recommendation about replacing the fuel filter. Remove the spare tire and it's easy to access.

My 2001 Pathfinder (VQ35DE instead of VG33 engine) got similar gas mileage. I don't think it'll be improved much for a vehicle that has the aerodynamics of a vending machine on wheels.

 

[stanlee]

You gotta be kidding. I take it you haven’t owned many midsize SUVs from the mid 90s/early 00s. If your 30 year old Pathfinder is getting 16.9 mpg TODAY considering yourself lucky after decades of drivetrain, engine and fuel system wear. Are you not aware it has a 16mpg combined (15city/19hwy rating) and EPA ratings, especially back then could rarely be duplicated with rear world driving.

 

[Hirev]

You have many things working against you.... 4000 lbs + your weight, poor aerodynamics, 1990s technology to name a few.

Looks about right on Fuelly.com.

https://www.fuelly.com/car/nissan/pathfinder/1996

 

[grasscutter]

You might have to start doing what I do, drive 10 mph below the speed limit everywhere you go.

It's really pointless to drive the speed limit anyway because all you accomplish is waiting longer at the red light.

 

[gman2304]

Actually Not too bad for a 90’s V6. My 95 Nissan 2.4 4wd 5 speed truck that I bought new, got 19 mpg on a good day.

 

[Albin]

Edited the OP to include changing out the fuel filter while getting tuned up.

Thanks!

 

[Albin]

Dump the WIX oil filter...

Why?

 

[Zee09]

Why?

Do a search here on your specific model...pictures are on here

 

[JavierH19]

Gas mileage is about 16.9 mpg. Most travel is TN rural 2 lane roads; very little stop and go traffic - usually towns with 2-3 traffic lights.

I'd agree. Start with plugs go for the fine twin tip ones from denso or ngk and a maf cleaning. I would say to run some redline sl-1 since the injectors are probably dirty unless you run top tier all the time. I didn't until costco opened up near me then my tank average mpg crept up after running it every week during the year then bought an obd reader and saw my fuel trims were within plus minus 1.5% on my old trucks after almost 2 years of running it. It's most likely still cheaper to run regular with sl-1 than to buy shell v nitro plus every tank and it would perform better still. Buy a pack on amazon for a better price.

 

[BrianF]

While I cannot comment on the specific vehicle, I'll draw from my experiences on different vehicles. Much has already been said.

Ensure you are using the correct spark plugs, not sure if this engine is sensitive to other brands, metals etc. Have the correct thermostat in there. Some vehicles throw a code for coolant temp, some run rich until up to temp. Use the correct oxygen sensor as well.

My 2006 Trailblazer 4.2 wasn't throwing any codes yet but the thermostat was getting lazy. It never quite could get up to temperature. I noticed it as the dummy gauge was a hair off and my fuel mileage was lower than expected for my drive cycle.

Again, no codes but my oxygen sensor was not showing a good wave, but showing abrupt voltage changes.

After changing these out, it was back to normal and mileage went back to its normal not really great 18 to 19mpg.