Gents

 

Noticing a slight los sin MPG since i had car serviced. Plugs were changed to denso iridium, air filter changed to mann airfilter from ECP. Normally on my trip to work i can get 40mpg easily. Now since the service i am getting about 35ish... driving style hasnt changed. infact i drove like a  nun the whole way to work on the motorway to test it. Air tire pressure is fine.

 

Any suggestions?

 

 

Did the service coincide with colder temps ?

In colder weather we are all going to have a loss of MPG's.

Twinchargers  usually love colder weather if dry and you are doing more than 20 miles and oil gets above 80*oC, and you have Winter Spec 99 Ron.

70 MPH should give a nice 45 MPG.

(2,400 rpm @ 70 mph has the Turbo doing light work and the Supercharger on demand if needed.)

 

?

So which plugs did you have them put in, and did you stick with that 5w 30 FS Long Life oil, spawn of the devil / Castrol / Quantum.

 

(Not so sure on your MANN Air Filter, but probably not the cause of increased fuel consumption.)

 

 

 

Twinchargers not good if you have to sit de-icing and if the oil temp is not even reaching an indicated 50*oC in about 6 miles, 

or doing many more miles than that each trip / start up.

 

PS

You lowered the car did you not?

Have you had the alignment checked?

You will now have ground affect just like a race car, so sucked to the ground and drinking juice....

PPS

How are the headlights after lowering, are they adjusted?

Edited 8 December, 20178 yr by AwaoffSki

I'll need to check what oil the mechanics used.  Plugs were the densos from Opie oils. Same ones recommended in the plugs thread. As for the lowering. I only lowered it 30mm. I have lowered every other car I have owned by 30mm and never noticed any dip in mpg.

 

As for wheel alignment, no haven't had it checked. Haven't felt any vibration in my wheel when driving at speed to suggest they are out of alignment. 

Ps if 5w 30 is not recommended what oil should I have asked for. Cheers

That is the Recommended Oil and for Fixed or Variable Servicing. (VW 504 00),  but then VW that recommend never accepted there are Twincharger issues.

 

Next maybe go 5w 40 FS VW502 00.  & Fixed Servicing. each 9,400 miles or less.

( so Not Long Life Oil, possible short engine life.)

 

**I was not serious on the lowering putting up fuel use,  unless the alignment is off, then it can.**

This stuff is all basic, a car does not need to feel the alignment is wrong, many notice when the tyre wear shows quite soon, 

so saving an alignment check price costs in premature tyre wear.

 

?

So which Denso,  the SKJ ones,  were the gap at 0.7 mm,

  did the mechanic say, did you ask?

Edited 8 December, 20178 yr by AwaoffSki

Near zero or sub zero temps can easily take 5 mpg off Nando,which is why I asked if your service coincided with the loss of economy - obviously there are lots of possible causes but good to rule out the easy ones first

I drove various twinchargers for 5 winters passing Perth weekly, doing about 1,000 miles a month in them.

Twinchargers love cool fresh at around freezing. Really. 

 

Lots of vRS MPG threads in this section in the last 7 years.

http://briskoda.net/forums/topic/319834-vrs-mpg-only-please 

 

EDIT,

450 miles 45mpg thread sadly gone, must have been when forum updated.

Edited 8 December, 20178 yr by AwaoffSki

Long distance mpg can be hugely different to short/medium distance runs though !

Depends on Nandos driving/commuting pattern really.

Exactly, he said he drove all the way to work on the motorway like a nun.

So if that is in and around Glasgow and not how he normally drives then no wonder the MPG drops, once at 50*oC plus oil temp drive like you stole it.

 

Wet roads kill a Twinchargers MPG, and so does wind and many things, but cold winter air and Tesco Super Unleaded winter spec they love.

 

If the mechanic has the correct Spark Plug gap, and the Air Filter is not restrictive, and the alignment is correct.

Tyre pressures checked cold.

Then Brim to brim check not Maxidot trusted.

I'll check the plugs. I think people said the ones from Opie oils came at 4mm instead of the recommended 7mm. Is that right ? 

A member said he got those, and has a misfire now.

 

Did you get DENSO SKJ  or VK20?     Ask the mechanic what the gap was when they checked all 4 were set at the same gap.

 

 

Reset your Maxidot and see what it shows on the next trip over at least 20 miles.

Was the SKj densos. Out of curiosity what is preferred air filter for the vrs. 

The MANN filter should be fine.  Did it have an over sock on it, if it did you might try removing it, but not until after the winter maybe.

 

I used Wix Air  or Blue Print Filters but just because that is what i got from the Motor Factor.

I don't understand why colder air would result in improved MPG
Air expands when heated - cooler air should effectively result in more air in?
I would have thought that more air in would make the ECU increase the fuel injected?

Cold air never gives an improved overall average mpg - any theoretical gain in engine power is easily counteracted by oil viscosity,slower engine warm up,more use of heater fans/lights/heated windows etc sapping engine power and also leaving car idling whilst it defrosts.

We can get our Fabia up to almost normal average mpg at near zero conditions but it takes much longer than usual which is why I posted earlier that it depends on ones driving/commuting pattern and mileage.With the ambient temps we have at the moment I would expect to lose at least 3-5 mpg except perhaps on a really long drive.

YS53,

  A Twincharger Fabia,Polo, A1, Ibiza will have the coolant up to 90*oC in a few minutes even at 0*oC, and the Oil at 50*oC in 6 miles or so.

& at 50-60 mph have the Maxidot showing over 50 mpg when driving at 60 mph.

If i leave Forfar at below Freezing by Scone the Oil might still be at 80*oC and some winter nights i do 300 miles and the oil never gets to 90*oC 

and that is to Glasgow, then Edinburgh and back to Forfar.

Weekly i drive to Dyce, sometimes a couple of times in a day, day time and night time, same route, thousands of times then, 

hundreds in the same vehicles.

Why there was a thread 450 miles / 45 MPG.  One winter i kept strict records, but then i know every MPG of every vehicle i have ever ownered or driven for a few days since the 1970's.

 

Drive or ride the same routes every week for 40 years or so in all weathers and times of day and if you have OCD you know what fuel is used.

Drive the same model of car for 6 years or more and you know them well.

My Jimny has been doing the same routes for 19 years since i bought it at Belmont Perth and it does the same MPG what ever the weather and the same as it did in 2003.

(only change ever is dependent on tyre size or a dirty air filter or if a K&N was in. But then it is non turbo petrol.)

 

there is 23 miles from Broxden Roundabout to Kier Roundabout with 70 MPH Average Speed Cameras,  (same on the return journey.)

i can actually show you some nights the difference when a 0*oC or at 12*oC winter cold night or even like the 4  nights ago which was 12*oC.

 

The car has a Supercharger & a Turbo and an intercooler and i can guarantee and show you that the cooler dry air can better the efficiency of a twincharger over those 23 miles.

Be that just sticking with using the throttle or even with cruise control.

 

I also get this with my 2/0TDI 150 PS SCR DSG.

After all before i get to the Broxden Roundabout i have done 35 miles and the engine, oil and coolant is at temp be it the TSI or the TDI.

 

 

This is the never changing route if you want to know your MPG on a run in all weathers, seasons, wind, rain, snow or sunshine / schorcio,. 

and you can do all speeds constantly for 23 miles, 50 mph if you want or quicker, just not more than about 73-75 as an average.......

*If you want to hypermile, choose a Van, HGV or Bus and stay a safe distance back and draft that for 23 miles.*

 

 

 

 

 

 

 

 

Edited 9 December, 20178 yr by AwaoffSki

PS in Summer in warmer weather with Turbo / Supercharger / Performance engines / Normal engines, any engines and even some N/A

 

Coolant & Oil needs cooling to get the Coolant and engine and oil to the efficient cooling and operating temperature, say about 90*oC.

So cooling takes energy, fan / coolers and heat soak wastes energy as well.

So no defrosting, warming up time is shorter, but if the ambient and air intake temp is high then that needs cooling and that uses extra energy as does A/C.

Not rocket science.

 

Also warmer roads, tyres, more traction, that is friction,colder roads less traction,  and then warmer air less oxygen than cooler air at the same height above sea level and barometric pressure.  Well sort of.  You need more science than that.

Air temp at night or day s not the same as ground temp, there can be 2-3 degree C difference, Air temp is taken at 2 meters high, 

vehicle air intakes on car are less than a meter above the road level unless you have a snorkle.

 

Air & Ground temps example.

http://trafficscotland.org/weatherstations 

 

If you have a Twincharger engine see the difference of the MPG at about 6*oC or below on a route in calm weather, 

and another time at temps of about 16*oC and up to 26*oC and compare if you do the same speeds, same weight carried etc.

http://briskoda.net/forums/topic/352088-vrs-miles-to-a-tank 

 

^^^Found some of my old pictures in that thread. 

122 miles through Glasgow - Perth fuel in at Scone and home, Cold weather usual Twincharger MPG in the cold.

 

 

Edited 9 December, 20178 yr by AwaoffSki

All very interesting young man but we are not talking about your driving  and I was always talking about overall average mpg - not at a specific point on a journey - so ie calculated from fill to fill against mileage,mpg readout goes up and down as you drive due to many variables including temp/gradients/headwind etc.

Edited 9 December, 20178 yr by YS53

Not just my driving, i have looked after several peoples vRS's over the past 6 years, servicing them etc and know what the CAVE and the CTHE do for fuel consumption, 

be that standard or with remaps and with different tyres.  But that is just my experience so maybe means nothing.

I have just been involved with tuning engines since i was Karting before i was at secondary school, then bikes.

Running different fuels etc. & into Turbos and Superchargers and alcohol or LPG engines & water injection etc.

 

If VW had built the Twinchargers properly and developed them then the technology was great.

They did go ahead with Electric Superchargers & Turbos but to go with Diesels, AUDI's.

& thats messed right up.

They left Volvo to continue with the Twincharger development and they are successful and reliable.

But then the CEO of VW USA did go to be the head of Volvo for Geely in 2010. 

Then onto GM International.

 

Cooling very very important, and cooling takes energy, and that uses fuel, 

Intercoolers very important, & if you can start with cooler air, but have the efficient oil temperatures then you can get the power required with less energy / fuel waste.

'Simply Clever'.  if you do it right, ie correct components and engine management.

 

 

 

Edited 9 December, 20178 yr by AwaoffSki

Hahaha awayofski you really are a fountain of knowledge dude. Get yourself on mastermind. Specialist subject. Skoda! 

 

Anyway... I may have discovered the issue. I remembered that I filled up with shell v power earlier in the week after the service. Probably the only time I have used it since having the car. Normally I use Tesco 99. I'm attributing the lose of mpg to that. I filled up with the good stuff today and took it for a blast once ooil temp heated up and seems back to its best. Does shell v power really give less mpg to the 99 Ron. 

 

 

When the Shell V-Power Nitro + you get is 99 ron and the Tesco Momentum 99  is 99 Ron no difference.  Except the Shell Detergent / Additive that is a secret, 

No different from Tesco Momentum Detergent package really.  

 

But both are 99 ron Minimum, and what you get from Greenergy / Tesco as winter Spec can sometimes be 100+ octane in Scotland, 

sometimes Shell's is as well, but you never know.

 

So the Twincharger loves that Ethanol.  Great stuff.  Winter spec Petrol Tesco , Shell and all the others is less hygroscopic now until March or later.

 

If Shell V-Power Nitro+ was cheaper than Tesco Momentum i still would not use it in the UK.  On Continental Europe i would, 

you get 100-102 ron out of pumps depending in which Country or how near Test Track / Factories you are, or Cities like in Italy.

 

At least Tesco publish their testing results, good or bad, but mostly they are good obviously,,  pity Royal Dutch Shell do not.

388380a097b04fe693a8c27db8bb4974.pdf

6ca06d648b9541e78fa838fece4a1a23.pdf

Edited 9 December, 20178 yr by AwaoffSki

Hmmm. I was sure v power was 97. Do u think it was just a case of oil taking longer to warm up due to colder weather then

4 hours ago, AwaoffSki said:

PS in Summer in warmer weather with Turbo / Supercharger / Performance engines / Normal engines, any engines and even some N/A

 

Coolant & Oil needs cooling to get the Coolant and engine and oil to the efficient cooling and operating temperature, say about 90*oC.

So cooling takes energy, fan / coolers and heat soak wastes energy as well.

So no defrosting, warming up time is shorter, but if the ambient and air intake temp is high then that needs cooling and that uses extra energy as does A/C.

Not rocket science.

 

 

Hey we will need to move up north near you if cooling is a problem up there  

Down here in temperate perthshire I hardly ever use A/C - in fact I usually leave it off in 'eco' mode and we havnae melted in the car yet (except to run a/c occasionally to keep smells away).

BTW I do understand all the stuff you are saying but as a generalisation any advantages for engine power/efficiency are easily counteracted by the disadvantages of cold ambient temps (especially for shortish journeys) - if you look around car forums at this time of year there are usually a few threads about loss of mpg's.

I am not a rocket scientist but cold dense air also causes more aerodynamic drag (esp above approx 40mph) .

 

rgds baz 

Edited 9 December, 20178 yr by YS53

Now you are just being silly,  Perth usually is a few degrees warmer having travelled only 30 miles west to get there,

but why it is the Fair City, beside the Tay and Cities and Airports get built where the weather is calmer / milder/ fog and snow free.

(That is aerospace science.) 

 

What we were talking about was the Twincharger fuel consumption, 

we know about heating up time, denser air and all that, 

we are discussing the changes the OP experienced and why, he is not an inexperienced driver unaware of winter.

 

Cooling is not a problem but cooling a 1,390 cc engine producing 132-136 kW plus requires the correct oils, and coolant and uses energy, 

and the oil can heat very easily with spirited driving.

 

 

Nandovee,

When it was Shell V-Power it was 98 ron minimum, 

when they changed to Shell-V Power Nitro+ it became 99 ron Minimum in the UK.

 

Sainsbury, BP, Esso, Gulf etc Super Unleaded is 97 ron minimum in the UK.

If you can not get Tesco Momentum 99 maybe go for Sainsbury Super Unleaded 97 ron minimum.

 

Twinchargers can have bore wash issues.  Detergents are the last thing you need really with a Twincharger.

Detergent is Sodium and that is basically salt. As for 'Nitro +' well that is a Joke.

 

102 Ron 'Hiperflo 250' is lovely, but costs twice as much as Tesco Momentum 99, and sometimes on the Dyno 

the difference is not much.  I use it for special days though.   & sometimes add 50/50 with the Momentum 99.

http://www.revotechnik.com/support/technical/14tsi-twincharger-engine-issues 

 

Edited 9 December, 20178 yr by AwaoffSki