High fuel consumption after servicing.

[TheWanderer]

1 hour ago, e-Roottoot said:

@TheWandererSo what actual miles do you get from that brimmed tank?

Do you even get 30 mpg if you were to use 10 or 11 gallons of the fuel in the tank?

 

@automass

The gear number is right there all the time regardless of what you have the maxidot showing.

re your MPG.

So how far can your can go if you were using 10 gallons or around 45 litres?

 

It can vary between 28 and 32. Depending on the journey to/from work or shopping trips etc. It can be as low as 24 or so in slow traffic in town (which we shouldn't be having) 

[Ootohere]

@automass

So you might have noticed that on tyres there are stickers that show the likes of Economy with a A,B,C,D etc.

 

Then even if the same size of tyres the new ones might be a little bigger / greater circumference than the used ones they replace.

 

?

What tyres have you fitted?

?

Have you checked the pressure the tyre fitter put the tyres at and reset the TPMS?

 

 

Edited 21 March, 2021 by e-Roottoot

[ords]

37 minutes ago, Ecomatt said:

Not worse. As filters become blocked your ecu will adjust the parameters to suit. However performance will drop and yes economy may increase slightly because the engine isnt running at full power. 

MPGs can be affected by air temperature, air pressure, tyre pressure, trye brand, wheels out of alignment, type of oil used in the engine, spark plugs incorrectly gapped or torqued, gearbox oil pressure, fuel quality, type of driving, road surface, road surface temperature etc. There are so many variables as to why the mpgs have gone down and up I have never worried about it or got hung up over it. Unless the car is running badly .i.e misfiring or being generally sluggish I wouldnt worry too much about decreased economy.

 

The OP has said he's getting 20-30 miles less than he used to. I can't see a blocked filter making that much difference.

[Ecomatt]

9 minutes ago, automass said:

Before servicing I bumped into the curve and damaged two of my left tyres. Tyres were all almost nearly touching the minimal thread though except one. so I got the tyres changed from the corner tyre shop of the place I live  with a set of four (Budget tyre) around 3 or 4 days before servicing.

I think you have found your answer. Tyres will affect economy as they all have different grip levels.

[automass]

5 minutes ago, e-Roottoot said:

@automass

So you might have noticed that on tyres there are stickers that show the likes of Economy with a A,B,C,D etc.

 

Then even if the same size of tyres the new ones might be a little bigger / greater circumference than the used ones they replace.

 

Wow Shelock Homes, you solved the mystery. Tyres wren't that good in terms of fuel effeciency. I remember checking the label before buying but fogot the alphabet right now.  so you thinking because of brand new tyres the consumption decreased.

[Ootohere]

@automass   Sorry but you make it hard work as you missed the most important fact.

 

The boy that serviced the car could probably have told you about the change of tyres and possible change in fuel consumption.

[automass]

i got myself a Tyre pressure pump. so i set them 32psi all around. i check the pressure whenever i get time and adjust them all around. besides i got a small TPMS gadget where I can see the live pressure and temperatures of the inside air of the tyres.

[automass]

I didnt pay attention to those alphabets for fuel consumption and noise level. I used brand new sets of best specification tyres couple of years ago and didnt see much of difference in anything.

[ords]

5 minutes ago, automass said:

I didnt pay attention to those alphabets for fuel consumption and noise level. I used brand new sets of best specification tyres couple of years ago and didnt see much of difference in anything.

Yes, but now you're using budget tyres. That's why it's possibly a reason for the poor fuel consumption.

Have you checked the pressures since they were fitted?

[automass]

Most definitely. As i was getting pooor fuel consumption I checked the pressures by my own machine and yes they were all set to correct pressure by the tyre shop which was 32psi. i have checked them again a week ago and they stood all correct.

[ords]

Maybe Google the tyre spec  you're using now for noise & efficiency & compare it with the one's you had on before.

[automass]

On 18/03/2021 at 19:26, Ecomatt said:

It might be because the air filter previously fitted was clogged up. Now it is breathing more freely it will use more fuel to compensate the extra air going in. 

 

 

Air filter couldn't be clogged up as i changed the air filter as well as cabin filter myself 10 to 11 months ago. Air filter was pretty clean when the guy took it off and didn't really necessary to change this time. But still I did change it. It seems tyres to be blamed, but really guys this is unbeliebable.

[Ecomatt]

2 hours ago, automass said:

 

Air filter couldn't be clogged up as i changed the air filter as well as cabin filter myself 10 to 11 months ago. Air filter was pretty clean when the guy took it off and didn't really necessary to change this time. But still I did change it. It seems tyres to be blamed, but really guys this is unbeliebable.

Similarly old tyres will have lower rotational grip than new tyres. New tyres will give more resistance but also depending on what tyres you fitted will depend on how much extra. Usually A rated tyres will give better economy and G rated tyres the worst. What tyres did you fit and what tyres came off?

[automass]

I have checked the tyres. They are called Farroad (225x45 R17). Wouldn't be able to find the ratting of these tyres.

[langers2k]

Well it'll depend exactly which of their tyres you've fitted...

 

Just as an example, this eBay seller suggests 'a' Farroad variant is E rated for fuel: https://www.ebay.co.uk/itm/402098366545

[automass]

I guess, I got these tyres as i can see mine also says 94w XL. I got them fitted for £220 though.

[automass]

Just to let you know the consumption 289miles in 39liters. Previously I would get 330miles with this anount of petrol.

[langers2k]

289 miles on 39 litres is ~33.7 mpg

330 miles on 39 litres is ~38.5 mpg

 

 

To put that into context, the worse/best from a single tank in my vRS is 33.0 vs 41.95 mpg so its certainly within single tank variance. Might be worth measuring a few more tanks to confirm the fuel usage

 

Also you should bare in mind that:

- A to E rated tyres can change fuel usage by up to 5% (A to G is upto 7.5%)

- Used (2mm tread) to new (8mm tread) will effect the odometer by ~2%

- Not all 225/45 R17 tyres are even the same size which will effect the odometer

 

The reason I mention the tyre size is because a larger tyre will make the car think it's covered less distance and mess up your calculation by making it appear low.

 

A combination of the above factors can easily cause extra fuel use and also make the reported mileage seem to drop giving a large difference 

 

[automass]

I have just taken the picture of the label of my tyres. 

[MarkyG82]

Is that the tyre or have you chucked the sticker on something else?  If you image search the FRD26 it doesnt look like that.

 

I think @langers2k has nailed it.  Different tyre + new tyre + tank variation = your higher fuel usage.

[automass]

Thats the original tyre in front of the tyre shop in the corner of my house which i fitted in my car. As I was walking by, it cought my eyes and thought to share with you guys as somebody else was asking about the sticker. Its pretty bad, consumption grade is "E".