Fuel economy problems

Faults and Technical chat for the Volvo XC40
Alex_O
Posts: 88
Joined: Thu Nov 26, 2020 5:47 pm

Post by Alex_O »

My XC40 is going into the dealer tomorrow to see if they can figure out what's caused my fuel system to go completely nuts.

Up until a couple of weeks ago I was getting in the region of 480-530 miles from a tank (using Eco, Cruise control, and a gentle foot). Now I'm getting around 200-220 miles and can't use cruise control because it visibly consumes fuel like watching a clock (around 1/16th tank per 10 miles).

Needless to say, this is a really annoying problem. Has anyone else had similar?

Deleted User 3629

Post by Deleted User 3629 »

Wow that's like 12-mpg in cruse control? What XC40 have you got? Can you smell un-burnt fuel because if its not a read out fault and it is using so much fuel then surely some must be un-burnt and that could knacker your cat too?
Alex_O
Posts: 88
Joined: Thu Nov 26, 2020 5:47 pm

Post by Alex_O »

Oldie wrote: Tue Aug 17, 2021 4:31 pm Wow that's like 12-mpg in cruse control? What XC40 have you got? Can you smell un-burnt fuel because if its not a read out fault and it is using so much fuel then surely some must be un-burnt and that could knacker your cat too?
It's a B4 Inscription Pro MY21. I haven't noticed the smell of unburnt fuel but I tend to keep the windows up and aircon on low. Noticed today that it's also making a lot more noise than it used to.
Rifleman
Posts: 435
Joined: Wed Mar 21, 2018 2:21 pm
Location: Nottingham, UK

Post by Rifleman »

If it’s burning lots of fuel and making a lot of noise could it be it’s stuck in a low gear or in off-road mode?
XC40 | First Edition | 2.0 D4 AWD | Bursting Blue | 19" wheels | Ordered 11/03/18 | Delivered 19th October 2018.
blastpipe
Posts: 565
Joined: Tue Aug 28, 2018 9:04 pm
Location: UK

Post by blastpipe »

Brakes binding? Are any wheels hot?
T4 Auto AWD R Design March 2019
Felindre
Posts: 777
Joined: Wed Dec 23, 2020 2:19 pm
Location: South Wales, UK

Post by Felindre »

You can check the gear you're in by flipping back the gear selector, you go into manual and the gear number shows on the display. You can change up and down by flipping the selector right and left. Selector backwards again to return to automatic.
B4 AWD Inscription , Fusion Red, Blond interior. Drivers Assist, Climate, Tinted rear windows and Towing pack.
Ordered 14 Dec 20, delivered 10 March 21
qrt31
Posts: 172
Joined: Mon Aug 02, 2021 10:30 am

Post by qrt31 »

blastpipe wrote: Tue Aug 17, 2021 9:05 pm Brakes binding? Are any wheels hot?
This happened to my Audi A3 a couple of years ago. The brakes got VERY hot on one wheel and my mileage plummeted. Luckily I diagnosed it before it did further damage.
Alex_O
Posts: 88
Joined: Thu Nov 26, 2020 5:47 pm

Post by Alex_O »

No brakes seem to be binding, there's no noise like that and the wheels aren't getting any hotter. The noise sounds like a light blow in the exhaust, or like I've got a larger engine than the 2.0

Gear wise I still see the shift points on the tacho, but I'll have a go with the manual mode if the technicians can't find anything. Using the comfort mode to drive up to the dealer this morning it was reporting 41mpg and the fuel didn't visibly drop at the rate it does in eco, so I'm thinking it must be (somehow) a problem linked to that.
Deleted User 3629

Post by Deleted User 3629 »

Very odd - 41-mpg today seems about right - still can't see how 3-times the fuel can be injected into the engine without the smell of un-burned fuel, and do wonder if its a read out error rather than real usage - then again I guess you have checked that the fuel out of the tank has physically been used? Very curious and not something I have ever come across, even when I fitted 3-times over-sized jets onto SU carburetors back in the 80's - SU's and Webbe'rs - who can remember those??
fisherman
Posts: 62
Joined: Fri Jun 12, 2020 9:18 pm
Location: Lancashire

Post by fisherman »

Weber 45 DCOE, those were the days. 😁.
XC40 RDesign D4.Thunder Grey Climate Pack Park Assist.Tempra Spare Wheel.
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