[Eric_GM]

My GF just bought an auto, AWD 2.4 2015 GV with only 19k km (12k miles) and she's getting terrible fuel economy. It's about half of what's supposed to be. The thing is, she mostly does short trips in moderate traffic and she's averaging around 17km/h (~11mph) and 5.5 to 6km/L (that's about 13mpg US). That's probably a worst-case scenario efficiency-wise but that's still worse than expected. I've only seen those numbers in heavily modded GVs with big tires and whatnot. To put it in perspective, with its 66L tank it's doing less than 300 km. We've filled the tank 3 times now.

We know the history of the car, her elderly neighbor bought it new and barely used it. No crashes or mods or crappy repairs of any kind. It's basically a brand new car that was used as a grocery getter for all of its life.

Is that the kind of mileage we should expect from the 2.4 under such conditions? BTW, this is a 3rd gen GV, sold here until 2019 or so.

Thanks!

 

[2013GV]

Mine (2,4 4 cyl) around town gets about 16 US mpg but can go a lot lower depending on stop start and traffic. If im crawling at 20 kph, then watch the gauge drop. Don't believe the dash consumption either, its not accurate, measure fuel used over distance travelled.
Open road running at approx 60 mph it gets about 25 US at 50 mph, about 28 mpg

Mine was bad until it hit about 20,000 kms then it really improved in economy., once it hit 30,000 it all stabilised.
Remember these are 1800 kg in weight and full time 4wd

I have had mine show 9.5 mpg UK (8 US) without much effort when it was new

Right foot plays a big part in the economy. Using power mode in the auto definitely increases consumption

 

[Eric_GM]

Thanks, pal. Yeah. I have my own collection of crap cans, most of them with bigger engines and more cylinders and they are close or even better in economy depending on how/where I drive them, so I'm very surprised about how bad this GV is. The ~5.5km/L was calculated from the 3 fill ups, not the cluster computer. I've read it's a bit optimistic.

Hopefully it improves as kms go by, but I don't think I can convince my GF to keep it for too long. It's a shame because the car is practically brand new. I took the air filter out today just in case it was wrapped in plastic or something, and that damn thing is spotless, it even smells good.

My plan is to drive it a longer distance, just take it on a weekend trip or something and measure consumption to make sure it's around the expected ballpark when driven longer distances in less traffic. If it's still terrible then we'll have to let it go.

 

[2013GV]

These are not known for economy, but for where they can take you and reliability. Not fast, but you're not buying a speed machine.
At least you're not paying $3 a litre for fuel like we are here.

 

[bvs]

Hi Eric and welcome aboard
If it is a veehicle which has been parked up for long spells + only used for short journeys it might be worth checking for binding/sticking brakes.
Also depending on your local climate - if weather quite cold at the moment,that + short journeys will not be conducive to good mpg's.
As you already posted - good idea take it for a longer drive

 

[Eric_GM]

Thanks for the warm welcome, folks! I really hope I stick around. I love the car, it's pristine inside and out, still has that new car smell and it's this awesome shade of red (rare here). I do get attached to cars all too easily, it's a weakness of mine. I would keep it, knowing how reliable these are. With a GV in such state, whatever you spend on fuel you save on repairs and parts, that's what I tell my GF but that won't keep her happy for too long with 250km-300km fill ups. Around here gas is about 1.25 USD a liter (no ethanol mix or similar, luckily), so that's $80+ for a full tank which goes by in ~3 weeks as things stand right now.

She has a lower back injury and she needed a tall, upright seat since her previous car (a Sentra) was really regressing her therapy sessions. This GV was too good of a deal to let is pass, but it's probably the wrong car for the purpose. It was an impulse buy without doing a lot of research beforehand. I would "buy" it from her but I'm already hoarding too many, uhm... historic pieces of machinery. The 4x4 duties being fulfilled by an R50 Pathfinder.

I'll report back once we take it on a longer trip this weekend. We'll see if there's something wrong with the car or if it's simply not loving the way it's been used.

Good point about the brakes. I had that same thought last night actually and we let it coast in N down a ramp. Seems to be ok, but you never know if it's intermittent so I'll keep checking. The other really big factor is potential carbon buildup considering that it doesn't get to operating temp for a long while. Probably offset a bit by a lot of idling and fuel cleaning it up, but still likely deserving a good revving on the highway. At 20k I suppose I can redline it already, right? Manual says the break-in period is just 1000km or so.

 

[bvs]

Hey Eric - $80 every 3 weeks doesn't sound too bad ,you should try filling up in Britain LOL.
Hope a longer trip goes ok.
Personally I would not redline it if it has been long term owned by a 'senior citzen' (then again I never redline anything ),I would probably just drive it on the brisk side of normal.
But using lots of throttle would probably cost you MPG's.

 

[2013GV]

If its an automatic do not coast in N, very bad for the auto.

Hell, im doing a tank a week in mine just going to work. I live with the economy knowing that at the weekend I can head off to my favourite fishing spot with no issues.
It's still cheaper to run than a lot of other cars out there.

 

[Eric_GM]

Hey Eric - $80 every 3 weeks doesn't sound too bad ,you should try filling up in Britain LOL.

But we earn a lot less down here So we are probably in equal terms. I'll take your advice and not redline it but I'll do several long runs at 3 or 4k rpms

If its an automatic do not coast in N, very bad for the auto.

Yup. It was in the underground parking lot in the office and it was at most a 5m long ramp. My Pathy is an auto too and I never coast in N so no worries there.

 

[2013GV]

3400 rpm ish will be 60 mph in D

 

[2013GV]

Got cruise control? That gives me about 3 mpg better than my right foot can.

 

[Eric_GM]

Update: we took our GV this past Sunday and racked up some miles on mostly empty roads. It was a combination of highway and city driving, but again, remote places with very few traffic around. It did definitely better mileage-wise, but now I more clearly see what seems to be the issue:

Do these GVs (4x4, automatic) seem to be constantly engine braking? I lift off my foot from the accelerator and it immediately starts to lose speed. It almost feels like the regen braking on an electric car. It's not stuck brakes because all wheels spin freely in N and you can feel it's just engine braking. The problem is that specially at low speeds in the city, you have to keep some pressure on the gas always so it keeps momentum, and that of course consumes fuel.

I have an older Pathfinder R50, also 4x4 and also an automatic and it coasts in D way more easily. My experience with automatic transmissions is that they disengage the torque converter when stopped in D or when coasting, so it's strange the GV doesn't seem to be doing that. It's either a constantly engaged torque converter or the tendency to downshift too much, or both (even though you can't see which gear you're in, you can infer it by looking at the tachometer). If that's how auto GVs are, that's bad news.

 

[2013GV]

Update: we took our GV this past Sunday and racked up some miles on mostly empty roads. It was a combination of highway and city driving, but again, remote places with very few traffic around. It did definitely better mileage-wise, but now I more clearly see what seems to be the issue:

Do these GVs (4x4, automatic) seem to be constantly engine braking? I lift off my foot from the accelerator and it immediately starts to lose speed. It almost feels like the regen braking on an electric car. It's not stuck brakes because all wheels spin freely in N and you can feel it's just engine braking. The problem is that specially at low speeds in the city, you have to keep some pressure on the gas always so it keeps momentum, and that of course consumes fuel.

I have an older Pathfinder R50, also 4x4 and also an automatic and it coasts in D way more easily. My experience with automatic transmissions is that they disengage the torque converter when stopped in D or when coasting, so it's strange the GV doesn't seem to be doing that. It's either a constantly engaged torque converter or the tendency to downshift too much, or both (even though you can't see which gear you're in, you can infer it by looking at the tachometer). If that's how auto GVs are, that's bad news.

Yes they will engine brake, theres a few starts in the system, they adapt over time to your driving, and if they see a lot of off and on throttle movements they will leave the torque converter clutch engaged for longer to slow you down. Even more noticeable if its in power mode and with cruise control active. More and more vehicles are using this feature now. Suzuki sort of pioneered this back in the early 90s
If you're doing steady speeds on a motorway and lift off, they will coast like any other automatic.

 

[Eric_GM]

Is there a reset procedure for the transmission's adaptations? Say, like holding the accelerator down a few times in ignition or disconnecting the battery? Not that familiar with GVs.

 

[2013GV]

Nope, short of disconnecting battery for 10 mins. But that results in everything resetting back to factory. It will run like crap for a week and have really bad economy until it re learns things. Possible throttle relearn needed, but that's simple enough, can give you that procedure if you need it.

Driving style has a lot to do with it.
Drive at steady speeds, ease off throttle but don't take foot completelyoff as it sees this as wanting to slow down, at about 10% ooening( idle is 7% ish) , car detects you're coasting, leaves torque converter clutch engaged if you still have foot just resting on throttle, after about 3 to 5 seconds, and revs are ok, it will disengage clutch and coast, round town it will look at speed and determine based on speed and throttle whether to use coast or deceleration or slip mode. Mines fine, brakes when I need it to coasts when I need it to.
Take foot off pedal completely car thinks "need to start deceleration" leaves torque converter clutch locked, about 3 to 5 seconds later no detection of brake bring applied, coast signal is given to torque converter clutch and it disengages and enters slip mode.

Hit the brake straight after letting off the gas, clutch stays locked ( if in slip mode, locks up fully) to add braking until it reaches 3rd gear change down at about 35 kph then disengages, this one you can feel as its an all or nothing switch when it releases, like regen braking in an ev.

Clutch staying engaged on the over run wont do anything to economy as engine is in fuel cut mode and not providing fuel in any greater quantity than idling requires, about 0.8 litres per hour, 1.1 litres per hour if a/c is on ( this is in a 2.4 engine)

These autos have a " slip" mode where they partially disengage the converter around town, leaving it locked improves economy as you're not wasting power moving fluid round the converter. Mine ranges from 100% locked ( 50 rpm slip) to completely unlocked. I average about 60% locked round town on sz viewer, you can't feel it below about 45%, feels like its unlocked but its still providing some drive through the clutch.
Slip mode also gives you the nice silky upshifts these autos are known for.

 

[Eric_GM]

Got it. I'm usually pretty quick to adapt to a new automatic car but since I'm not the one driving it's going to be a bit harder to translate your suggestions into results.

My Pathfinder feels kind of the opposite, building up a ton of speed when going downhill, never downshifting, never engine braking and with the torque converter disengaged. I have to use the brakes a lot and even sometimes I've had to force it to stay in 1st in fear of cooking the brakes. Long gearing doesn't help either.

GF just filled up the GV again and it took 48L for 273km, meaning 5.69 km/L. Onboard computer says 6.1 so it's a bit optimistic as expected. Still surprised about those numbers. My very thirsty VQ35DE carrying more weight is in the same ballpark and my manual E39 528i with a modded engine is more efficient.

 

[2013GV]

These are not a fuel efficient engine by 6odays standards, but given its hauling 1800 kg unladen around a d us full time 4wd, its not doing too bad. My old mitzi rvr 4G65 finally time 4wd hit about the same economy but this has low range box.

Once you get used to driving it, I think you will like it, especially if you hit nasty stuff. Just resting your foot on the gas us enough to trigger it to coast, as long as its not seeing its accelerator pedal position at 0 its going yo interpret it as wanting to coast or drive.

Biggest thing, never touch the gas pedal when starting unless trying to clear a flooded engine.

5.69 km/l? You sure? Thats 16 mpg UK, mines getting 23 to 25 round town.

 

[Fade2bluishblack]

eak even I don’t get that bad economy thrashing mine up the hill climb on the coastal range near us at +100km/h, maybe a MAF clean is in order?

 

[Platypup]

I cannot understand why you get such poor fuel consumption, even for an automatic. I just came back from a country trip with a lot of (good) dirt roads and a lot of cruising in 5th gear (manual) around 100 - 110 Km/h. and after 510km it took 47 litres to refill the tank. City and suburbs normally tales about 50 litres after about 500 km travel.

 

[2013GV]

I cannot understand why you get such poor fuel consumption, even for an automatic. I just came back from a country trip with a lot of (good) dirt roads and a lot of cruising in 5th gear (manual) around 100 - 110 Km/h. and after 510km it took 47 litres to refill the tank. City and suburbs normally tales about 50 litres after about 500 km travel.

I'm getting about 450 to reserve light out of my 2.4 open road, about 390 round town