Reported economy in the toilet after air filter, oil and filter, and winter tyre change

[ALFAitalia]

Don't get much of that down here on the South coast.... which is probably why not only do I not fit winters, but I don't know anyone else that does either! Had no proper snow here since 2010 and I only usually have to scrape thick ice off a dozen or so times a year. But obviously if you live in the frozen wastelands above the M4 corridor I can see why you might!

 

[OneForTheRoad]

.

 

[st13phil]

Don’t we do this winter tyre thing every year, with the same arguments (and some falsehoods) dusted off and rehashed?

 

[OneForTheRoad]

Don’t we do this winter tyre thing every year, with the same arguments (and some falsehoods) dusted off and rehashed?

I'm on the fence , I fitted all seasons .

 

[Skd884]

Turned out it was better value and easier to get it done by someone with the right equipment and knowledge. Just got back from a helpful garage with an online connection to MB who were able to squeeze this quick job in, and we were able to come to a suitable arrangement.

What did they do?

Let us know if it improves your scenario.

 

[StMarks]

What did they do?

Let us know if it improves your scenario.

Adaption re-set on the engine ?? (After those new filters).

 

[MrGreedy]

What did they do?

Let us know if it improves your scenario.

As per @StMarks

Reset air filter adaptations, which tells the engine there is a new air filter with zero miles on, so the ECU forgets whatever it learned from running with the old clogged filter.

Whilst I was there, they also set headlight level sensors to zero, front and back, after I'd just fitter a new rear level sensor (unsurprisingly, new sensors pick up a random level because it's not been calibrated to the car. This one was reporting -31mm at the rear after install, so headlights were very low).

Got a decent drive Monday next week, so I'll get a chance to test any improvement

 

[MikeInWimbledon]

Don’t we do this winter tyre thing every year, with the same arguments (and some falsehoods) dusted off and rehashed?

Aye !

Along with shocked postings about batteries failing after the clocks go back, as a result short runs and a refusal to ever use a battery charger or conditioner.

While over on the Dark Side, BMW M Sport owners wonder why their suspension feels so hard, and why their Beemers tramline on poor surfaces.

 

[ChrisPDuck]

Reset air filter adaptations, which tells the engine there is a new air filter with zero miles on, so the ECU forgets whatever it learned from running with the old clogged filter.

Can someone explain to the less well-versed (me) why this would be necessary? Isn't there some sort of sensor (MAF?) that measures how much air there is and adjusts the fuel accordingly? In what way does the engine 'adapt' to an old clogged filter?

And will I need to do this to my 2010 E500 (M273) when I change the air filters?

 

[ALFAitalia]

Its not...


....and no. For the reason you said. It may make it adapt fractionally quicker but otherwise it will soon learn from MAF info etc. Even new filters will have so degree of tolerance in production and will flow slightly differently.....so the ECU will still have to learn even after adaptation .


IMO of course.

 

[Bellow]

This fella obviously has no clue what winter tyres offer . It's not all about snow . More about sub zero temperatures and hard summer tyre rubber.

No, it is actually all about snow. Bare roads no matter how cold are child's play. Driving in drifting snow where defining the road edges is partial guesswork is another order of magnitude more difficult. Not that I'd expect to find that in sneering Wimbledon. Really, if you've no experience of the topic, STFU.

 

[MrGreedy]

So, to the original question, could changing from one winter brand of tyres to another winter brand of tyres (see posts at beginning of thread for details and tyre ratings) cause an enormous drop in economy?

At this point the virtues of winter tyres is not worth discussing, as they are on my winter alloys and I'll run them over the winter, swapping to summer alloys and tyres in the Spring.

 

[ChrisPDuck]

So, to the original question, could changing from one winter brand of tyres to another winter brand of tyres (see posts at beginning of thread for details and tyre ratings) cause an enormous drop in economy?

It does seem rather unlikely, doesn't it? A 30% reduction in mpg just from the tyres? It feels like it has to be something a lot more significant than tyres - like binding brakes for instance, but you'd certainly notice the burning smell!

FWIW, I recently swapped from summer to winter tyres, and although I don't have much mileage on them yet, the dashboard mpg display doesn't seem to have registered any difference at all.

 

[Bellow]

So, to the original question, could changing from one winter brand of tyres to another winter brand of tyres (see posts at beginning of thread for details and tyre ratings) cause an enormous drop in economy?

I don't believe so. Changing to winter tyres (with the snow and peak symbol) from Pilot Sports on my smart, and from road biased tyres to All Terrain type on my Suburban didn't impact fuel economy to any noticeable extent. That pretty much covers the lightest (730kg) and heaviest (2700kg) cars you'll find on UK roads and the results were the same. Given that changing from summer to winter/AT made no difference I can't see how a change in brand of the same tyre type can be responsible for your loss of economy.

 

[OneForTheRoad]

No, it is actually all about snow. Bare roads no matter how cold are child's play. Driving in drifting snow where defining the road edges is partial guesswork is another order of magnitude more difficult. Not that I'd expect to find that in sneering Wimbledon. Really, if you've no experience of the topic, STFU.

I was talking about the other fella , so maybe it's you that needs to stfu as you say .

 

[Bellow]

I was talking about the other fella , so maybe it's you that needs to stfu as you say .

And I wasn't referring to you. Unless you are also in Wimbledon....

 

[OneForTheRoad]

And I wasn't referring to you. Unless you are also in Wimbledon....

So who's stfu then ? I'm confused now . Him or me .

 

[st13phil]

So, to the original question, could changing from one winter brand of tyres to another winter brand of tyres (see posts at beginning of thread for details and tyre ratings) cause an enormous drop in economy?

While different tyres can make a difference, I can't see it making the degree of difference that you reported.

For example, I swapped the original Hankook Ventus S1 Evo2 tyres that were on my W177 A-Class to Conti Premium Contact 6's and it's definitely resulted in a modest (circa 3%) increase in fuel consumption which is nothing like the massive drop you reported. The far superior wet grip of the Conti's more than offsets the tiny additional fuel cost though.

When I ran diesel cars I always noticed an increase in consumption during the colder months even though my usage pattern (25+ mile commute in each direction on fast A- and B-roads with little congestion) was unchanged. I always put that down to the switch to winter blend fuel which is normally available from 15th November to 15th March each year, as that has a marginally lower energy content per unit volume.

 

[OneForTheRoad]

And I wasn't referring to you. Unless you are also in Wimbledon....

I see now , thanks for that

 

[190]

Agree it can't possibly be all down to the tyres.

Tyres are graded A to G rating, with A-rated tyres being the most fuel-efficient and G-rated tyres being the least fuel-efficient.

There is a general lack of clarity about what precisely the A to G rating means. The grades are defined by the coefficient of rolling resistance expressed in kilograms per tonne with an G grade almost twice as high as A. But tyre rolling resistance is only a small part of fuel consumption so it's reckoned that difference between the best and worst rating in mixed use is typically 7.5% of a cars overall fuel consumption. It depends on how the car is used. At higher cruising speeds rolling resistance represents a lower proportion of the fuel consumption therefore the maximum difference would be less than 7.5 %.

Tyre pressure is another factor but the difference it makes is surprisingly small. A 10% reduction in pressure typically increases fuel consumption by only 0.8 %.

It seems to me from the above that it would be impossible for tyres to make a 30 % difference in fuel consumption.

Class	(CR) in kg/t
- A -	6.5
- B -	7.15
- C -	8.4
- E -	9.8
- F -	11.3
- G -	12.1

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