Subaru xv service / glow plugs

[aidy55]

Ive recently bought a subaru XV, running fine but MPG is down, only 38.6mpg.

Its 2012 2.0d.

 

Ive changed the oil, oil filter, air filter and cabin filter. I can manage tje basic things but the fuel filter looks very complicated, maybe that will help with mpg, has anyone here tackled the fuel filter. 

Im just wondering aswell are glowplugs part of maintenace, when should i change them or do you just change them when they stop working? I know spark plugs affect mpg but not sure if gloe plugs do. 

Also any recommendations on best wipers for subarus, the ones i have one sont wipe rain away at all lol

[ernieb]

I don't have a diesel version of the XV but have had plenty of diesel powered cars over the years, my advice for what it's worth is leave the glowplugs alone. I don't know for sure but believe they are a pain to change anyway.  I've never experienced a failure or extended warm up and can not see how they will contribute to the fuel efficiency in the same way as spark plugs might do.  The diesel is fired by the engines compression and the glowplugs  just to start the cars engine. If the glow plug light on the dash goes out in a reasonable time every thing should be OK.

I'm sure you'll get some better expert advice.

[ernieb]

Sorry missed the last part of your question, I use Bosch replacement wipers, whatever you go for make sure you look in the correct manufacturing year range.

[Judd]

Honestjohn's real mpg https://www.honestjohn.co.uk/realmpg/subaru/xv-2012, as submitted by owners of the cars, shows average real mpg to be 47mpg, so you arn't that far out, depending on the use your car gets, terrain travelled, periods of constant running versus multiple junctions bends urban stop start driving and last but not least how you drive, no criticism here or suggestions you are doing anything wrong, but many drivers do not use terrain correctly or allow the vehicle to drop speed via overrun etc, we are all guilty of less than perfect economy driving to an extent, that 38.6 might be quite reasonable.

Glow plugs generally only work for up to a minute if that at cold start, they do not continue to operate once past initial running phase, and unless your car displays difficulty when cold starting ie one or more cylinders misfiring till they get warmed up enough to fire i wouldn't worry about them, remember glow plugs in many modern engines have a nasty habit of snapping off in the head when you try to remove them (big expensive job), so best left alone unless they actually fail.

Being a typical Japanese car my first action would be to strip out, inspect and clean the brakes, exercise the pistons in their bores to make sure they are free to move and lube everything that moves with the correct red brake grease upon reassembly, particularly any sliding pins, include the park brake if its the drum inside disc design (rear discs have to come off for access)..i have no idea what system of park brake the XV uses, i'm speaking generally of most well made Japanese cars which haven't gone over to satan's electric parking brake of doom...edit, nope i see a proper park brake lever so should be the very best of all rear brake designs, drum inside disc.

A good check for binding brakes and wheel bearings is to select a suitable stopping point on a longer journey you make that you can come to a halt in without touching the brakes at all, ie a long layby uphill on a long quiet dual carriageway, where you can use the hill to stop, then once stopped have a feel around the brakes and hubs for any excess warmth.

Also check tyre pressures and look at the treads for uneven wear that could indicate an alignment issue, i don't think your fuel usage is that far out that it's more than a minor issue causing the lower than average, if anything.

edit, one other minor thought, proper AWD cars like Subarus require very similar tyres and tread depths all round or the various diffs can be working continually to adjust for rolling radius of mismatched tyres (leading to slight drag and excess wear to diffs), also more rugged all terrain or full winter tyres usually use more fuel than standard summer style tyres.

[Judd]

One other thought, is it getting the right sort of motoring to allow the DPF to regen adequately, has it regenerated in your ownership time to your knowledge?