Reduced mpg with winter tyres

[Numbercruncher]

Since swapping from the standard tyres to winter tyres, my average mpg has dropped to low fifties.  I was averaging sixty mpg on the summer tyres.

 

I've got a Superb Greenline with 14000 miles on it.

 

Is it normal for average mpg to drop by that much?

 

 

[Always time for a car]

I have quite the opposite. I run standard size 18" Vredestein wintrac extremes during the winter and I get an average of 5mpg more on the winters on a decent run. Most likely because i drive a little cannier so I do not deplete the tread too quickly.

[Gizmo]

+1 I get slightly better MPG on my 205/55/16” winters compared to my 225/40/18” ‘summer’ tyres, however as the Greenline uses 205/55/16” as std then I would not be surprised that an identical sized winter tyre uses slightly more fuel.

[Tatt]

From 225/40/18 to 205/55/16 your speedo will read slightly faster by a full half a mile a hour lol, But it just make that slight difference. But I would of still went for the softer compound tread making it use more fuel.

[LS108]

Since swapping from the standard tyres to winter tyres, my average mpg has dropped to low fifties.  I was averaging sixty mpg on the summer tyres.

 

I've got a Superb Greenline with 14000 miles on it.

 

Is it normal for average mpg to drop by that much?

1. What was the pressure in summer tires and what is now?

2. What are your driving conditions? Short dictances or long?

[Gizmo]

1. What was the pressure in summer tires and what is now?

 

That’s a good point, winters should run at +0.2 bar higher than your normal tyres. 

[T. Spark]

I saw a massive nose dive in mpg with winter tyres... around 8mpg!

 

However I have put it down to the weight of the wheels (different wheels) and the profile / psi of the winter tyres too.

 

Not that I needed to put winter tyres on so early in the end, but oh well.

[wiilydog]

It will likely be the change in circumference of your wheels causing the no miles travelled to vary +/-

Also depends on the rolling resistance of your winter tyres

[Cemesis]

Since swapping from the standard tyres to winter tyres, my average mpg has dropped to low fifties.  I was averaging sixty mpg on the summer tyres.

 

I've got a Superb Greenline with 14000 miles on it.

 

Is it normal for average mpg to drop by that much?

 

Don't panic, I have exactly the same. The winter tyres are clearly stickier (you can feel it when they are new) and thus have more rolling resistance which decreases ecconomy. I would get very high 50's or low 60's in the summer but am getting 53mpg in the winter. Same car as you.

[silver1011]

The Greenline is fitted as standard with more efficient tyres - one of the unique credentials that allow it to achieve the higher MPG and the 'Greenline' tag. 

 

Swapping these for a set of less efficient winter tyres will inevitably reduce your MPG.

 

Those with 18" Thermisto's or Luna's running summers then changing to 16" winters will likely see an improvement in MPG as a 16" steel / alloy is a lot lighter than the 18" Skoda OEM alloys.

[Numbercruncher]

Thanks for your replies.  Makes more sense now.

[JB.]

As one the previous posters, I actually saw an increase in my MPG readings when going from summer to winter as it was reducing from 18'' alloys to 16'' steels.

[silver1011]

All of Skoda's fuel efficient 'Greenline' models are fitted with 16" wheels.

 

There is a good reason for this in that they are a lot lighter than the larger wheels and together with the unique tyres offer a reduced rolling resistance.

 

Fitting winter tyres to 16" rims won't offer the same reduced rolling resistance and the OEM summer tyres but the weight reduction of a 16" steel versus an 18" alloy (multiplied by 4) will almost definitely help reduce fuel consumption.

[dippo]

Fitting winter tyres to 16" rims won't offer the same reduced rolling resistance and the OEM summer tyres but the weight reduction of a 16" steel versus an 18" alloy (multiplied by 4) will almost definitely help reduce fuel consumption.

I thought alloy wheels were meant to be a lot lighter than steel wheels, so will there really be any great weight reduction between a 16" steel and an 18" alloy?

[silver1011]

Alloy is lighter than steel but due to the construction of wheels it is very rare for an alloy wheel to weigh less than an equivelent sized steel wheel.

[Yearofthegoat]

I thought alloy wheels were meant to be a lot lighter than steel wheels, so will there really be any great weight reduction between a 16" steel and an 18" alloy?

 

I can say for sure - having lifted the wheels about when changing them over - that my 18" Themisto alloys with Sport Contact 2s on are noticeably heavier than 16" steels with Nokian winter tyres on.

 

And I guess that's why I get about 4mpg more with the winters on the car.  Makes me consider selling the Themistos!  But I like the 18" look too much.

Edited 11 January, 2014 by Yearofthegoat

[Cemesis]

I thought alloy wheels were meant to be a lot lighter than steel wheels, so will there really be any great weight reduction between a 16" steel and an 18" alloy?

 

Alloy wheels are much thicker and hence heavier.

[LS108]

Well,  weight difference related with wheels on a big family passenger car has the same impact to fuel economy as having full or half empty tank

 

In most cases those are the combination of reasons which influence worsening fuel economy during winter:

 

- lower outside temperatures (main one)

- rolling resistance of tyres (especially on snow)

- incorrect tyre pressure

- longer periods of idling while cleaning the car from ice and snow

- driving with lower gears when slippery or cold

 

Reasons for improving fuel economy during winter - driving slower when slippery + gentle throttle control. 

[Freshacre]

As an aside to the main thrust of the thread, I noticed during 50k miles in the Yeti on either the normal tyres, or the winter tyres when fitted, that the biggest change to my mpg occurred when the temperature changed.

As the ambient temperature plummeted, so did the mpg on both types of tyre, by as much as 5mpg. Since the advent of smartphones and apps I have been recording every fuel purchase, mileage, conditions and use, and since I always fill to the brim, usually at the same pump, I reckon the data is pretty accurate.

[cobreti]

Hmm, how accurate is the on boarding computer when it calculates mpg? I figure there will be some errors because of that the car doesnt know the circumference of the wheels?

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