Tyre change = lower mpg?

[dave dean]

I just wondering if anybody else has experienced a similar effect / problem.
I changed all 4 tyres on my Glc 220d, from Vredstein to Michelin cross climate all season after 40,100 miles
three weeks ago & I have noticed a significant drop in mpg on short and long runs.
( its dropped approx 6mpg around the doors & 11mpg on a long run)
I did check reviews of this tyre on trust pilot before purchasing & most were 5* for better handling & only a minimal difference in mpg.
However I don't class 6-11mpg minimal.
My tyre pressures are correct & driving style has not changed & car is not due for a service for another 1800 miles so this cannot be the cause?.
I always thought that Michelin were a premium brand?
My concerns are I have read several reviews on forums stating that on the next scheduled service an MB software update for emissions will be done and people are posting they are finding a 10- 15% drop in mpg afterwards
So after spending 1k on new rubber I cant afford to change tyres & will be bankrupt / divorced if the mpg continues to drop.
Thanks for reading but I would appreciate it if anybody had any thoughts on this.

 

[Blobcat]

I used to notice a drop switching from summers to winters on my W213 so it’s very possible that the new tyres are having a negative effect.

It’s also been colder recently so the car will take longer to get to temperature so will use more fuel.


You could try upping the tyre pressures as that generally improves economy

 

[dave dean]

I used to notice a drop switching from summers to winters on my W213 so it’s very possible that the new tyres are having a negative effect.

It’s also been colder recently so the car will take longer to get to temperature so will use more fuel.


You could try upping the tyre pressures as that generally improves economy

Thanks for the advice . I will give it a try upping the pressures as running at recommend 2.2 bar / 32psi at the moment

 

[Peter Marshall]

Just wondering if there is say 6mm of new tread greater than the old then that would be a 12mm greater diameter of the new tyre. Therefore the odometer will read proportionally less mileage, if anyone is good at maths perhaps they could calculate if this could be significant?

 

[Wighty]

Just wondering if there is say 6mm of new tread greater than the old then that would be a 12mm greater diameter of the new tyre. Therefore the odometer will read proportionally less mileage, if anyone is good at maths perhaps they could calculate if this could be significant?

Like your thinking buddy

 

[mioba]

Ever wondered why there is a fuel consumption sticker on new tyres

 

[sonic]

I change from summer 18" to winter 17" each autumn, consumption improves by about 2 mpg initially.

 

[dave dean]

Ever wondered why there is a fuel consumption sticker on new tyres

Yes I saw the grading prior to purchase hence I checked out reviews on trust pilot & the overall opinion was there was no significant decrease to mpg.
Maybe next time I wont be so dependant on the trust pilots reviews?
Thanks for input

 

[dave dean]

I used to notice a drop switching from summers to winters on my W213 so it’s very possible that the new tyres are having a negative effect.

It’s also been colder recently so the car will take longer to get to temperature so will use more fuel.


You could try upping the tyre pressures as that generally improves economy

** Blobcat. update .. I have tried upping pressure slightly & it has had made a big difference to mpg straight away.
Thanks again for suggestion

 

[mersum1es]

In Finnish tyre tests they measure rolling resistance, difference between tyres can be up to 5%. Then if size of the tyre changes, effect could be even greater (my own experience, over 10%)

 

[dave dean]

In Finnish tyre tests they measure rolling resistance, difference between tyres can be up to 5%. Then if size of the tyre changes, effect could be even greater (my own experience, over 10%)

Thanks for the input

 

[Eddie fh]

Mine dropped about 4-5 mpg on the trip computer since moving to cross climate

 

[dave dean]

Mine dropped about 4-5 mpg on the trip computer since moving to cross climate

Thanks for the input ... think I will need to do more checks before buying Michelin tyres again.. as the decrease in mpg does make a big difference over 12 months

 

[Blobcat]

Thanks for the input ... think I will need to do more checks before buying Michelin tyres again.. as the decrease in mpg does make a big difference over 12 months

Any low rolling resistance tyres will make a difference

 

[matthew k]

I think the manufacturers self report the ratings? I noticed quite a large drop after changing my rear tyres, 245/40 18 I think, quite wide. I used budget tyres as I don't exceed 70 mph, and seemed to loose 4 mpg when cruising on the M way. I think they can make a surprising difference.

 

[dave dean]

Thanks for the input .. I am running on 255/45/20

 

[rf065]

Watch out for the wear pattern if the pressures are increased, you could find yourself needing new tyres sooner than you think and that's going to cost more than the difference of a few MPG's.

 

[umblecumbuz]

Colder weather, which will affect engine efficiency as well as tyre suppleness, slightly larger diameter of new tyre, initial material stiffness - a plethora of small differences can add up.

 

[dave dean]

Watch out for the wear pattern if the pressures are increased, you could find yourself needing new tyres sooner than you think and that's going to cost more than the difference of a few MPG's.

Cheers ... was only going to run a slightly higher pressure for a while .. just until weather / temperature picks up & then revert back to MB recommended pressures of 2.2 bar & then see how it goes from there

 

[dave dean]

Colder weather, which will affect engine efficiency as well as tyre suppleness, slightly larger diameter of new tyre, initial material stiffness - a plethora of small differences can add up.

Thanks for input.
The 20inch rims & 255/45 tyres were already fitted when purchased as a demonstrator. I think the standard rims are normally 19inch