Inflating Winter tyres in Summer

Ermia

I made a mistake. I did not know about Winter and Summer tyres. Recently, I had a puncture in a weekend and rushed to a tyre shop to get a replacement "part-new" (as the puncture was severe), and the tyreman suggested that two of my other tyres need replacement, too. 

He offered a bunch of almost-worn part-new in stock but were very close to the legal limit, so I refused. Then, he offered some good Dunlop tyres with plenty of tread, but had an unusual pattern. I was desperate so I accepted the offer, so he replaced three of my tyres (both front ones and one of the rear ones) with Winter ones. 25 quids each. pretty good price.

Then I got home and searched about the tyre pattern. I learned that these are winter tyres, and their lifetime (from new) is 15k miles (compared to 55k for all-season ones). I also learned that they reduce MPG by 5%-10%. 


Now, I understand that the "proper" solution is to replace them with all-season ones. However, from a Money Saving point of view, I wonder if this is worth it because I don't have any space in my room to store them, so if  I replace the tyres, I have to throw out the winter tyres. Also, it's a Cat-S old Toyota Yaris 2008 that is not spending much on. 

Nonetheless, I have two concerns:
1. To what extent are winter tyres unsafe to use in London's summer? I checked the tests and they show only 2%-5% more braking distance compared to all-season ones. Is that really important? or can it be compensated with driving habits? Also, do these melt in London's summer weather?

2. From an MPG point of view, I understand that winter tyres use more MPG. I wonder if the 5%-10% figure that I read from other forums (someone's ideas) is actually accurate? Of it's more than 10% increase in MPG, then it's best to throw these in bin and get another set of all season ones, but does the winter ones really decrease fuel cost more than 10%?

3. Does slightly over-inflating tyres help compensate for the loss in MPG? My car's manual suggests 32 PSI for normal use and 36 PSI for high-speed use (above 160km/h). I'm 50%-time in London motorways and 50%-time in London streets. I was thinking: "If winter tyres use more fuel because they are too soft, and inflating tyres make it hard, then maybe if I use maximum suggested PSI (36), then this could compensate the softness of treads and make "winter tyre + 36 PSI" have the same "softness" as "all-season tyre on 32 PSI". Is that a good thing to do?

Thank you!
P.S. Here is how the tyres look:


And my only all-seaon is like this:

forgotmyname

UK is winter 11 months of the year.  You bought cheap tyres, what makes you think they are any worse than the other
budget options?

Ermia

forgotmyname said:

UK is winter 11 months of the year.  You bought cheap tyres, what makes you think they are any worse than the other
budget options?

That's a good point. If my winter tyres increase fuel consumption by 15%, that's roughly an extra £100 per year (15% of my £700 annual fuel cost). That would be more than the cost of replacing them now with part-new all-season ones (£75 to replace the three of them).

My main question remains - will these winter tyres really hike my fuel bill by over 15%? And if so, can slightly over-inflating them help bring that down a bit, so I can avoid replacing them for now?

Thanks again for your input.

molerat

IMO the bigger concern is the mix of winter and summer on the rear axle which can cause an imbalance in handling.

mgfvvc

Ermia said:

My main question remains - will these winter tyres really hike my fuel bill by over 15%?

Probably not, there are too many factors involved to say definitely. I suggest driving on them until you've used a few tanks of fuel and seeing how it goes.

Ermia

mgfvvc said:

Ermia said:

My main question remains - will these winter tyres really hike my fuel bill by over 15%?

Probably not, there are too many factors involved to say definitely. I suggest driving on them until you've used a few tanks of fuel and seeing how it goes.

Thanks for the input. Yes, I think that's what I should do.

Though the challenge is that my fuel consumption varies a lot by many factors such as usage pattern and season , and the #1 factor is the temperature (consumption in winter is much higher, as you can see the red/green seasonality of MPG in my refuelling data below). So it will take a long time until I can conclude whether winter tyres had any significant effect on consumption.

molerat said:

IMO the bigger concern is the mix of winter and summer on the rear axle which can cause an imbalance in handling.

Is this a concen in a front-wheel drive car? What sort of test/maneuver could help identify if this is serious?

mgfvvc

Ermia said:

molerat said:

IMO the bigger concern is the mix of winter and summer on the rear axle which can cause an imbalance in handling.

Is this a concen in a front-wheel drive car? What sort of test/maneuver could help identify if this is serious?

As the rear wheels are neither driving, nor steering it's less of an issue, but still could be tricky in the wrong conditions. Essentially in snowy/icy conditions one corner of the car has significantly less grip. If you drive carefully, it should be OK, but you need to be aware of it and drive appropriately. I'm not sure how you'd test for it without taking it to the Volvo test track in Sweden.

Bigwheels1111

I have used winter tyres for years.
About 15 year in total.
Put them on in late October and off in March.
They are only good for 3 years, as the silica starts to harden.
On the third year I would run them until they wore out.
As I was cabbing and doing 30-50k a year I would go through 1.5 to 2 sets of tyres a year.
Fuel consumption was not that big an issue.
Just use them until they wear out, then stick a good set of new tyres on.

baser999

Not sure where you get a figure of 55k miles out of a set of all-season tyres? Personally, I’d have not touched those tyres, no idea of their history. Why not buy a proper set of tyres; they’re the only things keeping you on the road, why compromise. 

As I say, just a personal opinion

35har1old

baser999 said:

Not sure where you get a figure of 55k miles out of a set of all-season tyres? Personally, I’d have not touched those tyres, no idea of their history. Why not buy a proper set of tyres; they’re the only things keeping you on the road, why compromise. 

As I say, just a personal opinion

I agree that I can't see you getting 55k out of any type of tyre.
It would take you be having wheel alignments done constantly especially if your drive in areas with speed bumps

chrisw

First time I've heard of part-new tyres! The difference in fuel consumption will be negligible compared to he other factors such as weather, air con use and traffic, particularly if you are primarily depriving around London. No two journeys are ever the same so comparisons will be difficult anyway.