I've been running Goodyear Ultragrip gen2 for a few weeks inplace of the P7s

I have noticed I'm easily getting over 45mpg now compared to high 30s when I had the P7s fitted??

 

Anyone else had the same effect. Rolling radius is the same (235/40x19 vs 215/60x16)

45 minutes ago, Q102 said:

Rolling radius is the same (235/40x19 vs 215/60x16)

Tyre width is different. I don't know about speed index or load index (not quoted), or tyre pressure (also not quoted) but these all have a bearing on fuel economy. So can use case, air pressure, relative humidity...

@Q102  Did you actually run a tape measure around the different tyre to be sure the Total Circumference is identical and the mileometer is reading the same for the different tyres?

(Rather than going by a tyre calculator.)

Edited 31 January, 20224 yr by roottoot

I suspect the wheel / tyre combo is quite a lot lighter, which should account for some of the difference.

Lighter, narrower, more sidewall (less rolling resistance). The same tyre size in a more summer oriented model will probably offer more mpg again.... All other conditions being the same of course. You need to take into account air temp, road surface, journeys travelled etc etc.

@brettikivi I do so wish that others would sit the wheel with tyre on a bathroom scale or any scale that is good for at least 23 kg so that they do know the difference from ones they are changing.  (as well as putting a tape measure around the tyre.)

Same with Spare Wheels & tool kits etc.  

When Hyundai released official consumption data for models of their Hybrid Ionic (I think) I was surprised at how much difference there was between the lower spec model with relatively skinny small wheel/tyres and the higher spec 'sporty' model with larger wheel and wider low profile tyre.

These were derived in laboratory conditions but not far short of what the OP seems to be experiencing.

They know to behave.

Hyundai / Kia are a big manufacturer in Europe and Globally and know not to cheat or be caught cheating.

Especially by South Korea.

 

No surprises with the German Owned Companies & the EU and the WLTP  or the tests before as they were on 'a model' without options on a rolling road or dyno and fiction anyway as the tyres could be over inflated.

 

 

Then VW Group brands SEAT, AUDI or VW were doing their own testing and there might well have been diesel in the engine oil of TDI's.

 

RDE & RDE2 have caught then out so they had to mess with the Engine Management of 1.5 TSI's and the DSG's to get WLTP figures and have had to mess about since to make the vehicles drivable and meet the Original Test results or not as the case is for some with early WLTP Certificated cars.

 

Hyundai / KIA know that cheating or inaccurate fuel consumption figures can really cost them as Hyundai - KIA found out in North America and Canada years back.

They ended up after a court bent them over having to give owners Fuel Cards.  

 

VW Group get a kicking in the US for being cheats but the EU says on you go we will give you a new test regime that you can find grey areas with and if we catch you with Implausible C02 emissions then that is just a snagging issue.

 

 

 

 

Edited 31 January, 20224 yr by roottoot

Yes I also get improved mpg even though it's winter conditions.  My All Season tyres are mounted on the 17 inch rims with 215/55 R17 whereas on the summer set with marginally greater fuel consumption are 235/45 R18.

On 02/02/2022 at 04:24, MrRich said:

Yes I also get improved mpg even though it's winter conditions.  My All Season tyres are mounted on the 17 inch rims with 215/55 R17 whereas on the summer set with marginally greater fuel consumption are 235/45 R18.

How do you find the ride and noise levels on the winter tyres compare to the summer set?

Edited 4 February, 20224 yr by Gerrycan

The Continental All Seasons aren't a full winter but can work in winter conditions (to a point).  I think the tyre and rim size suit the car well for good ride and low road noise.  I would consider 17 inch rims for my summer tyres as well if I didn't already have the 18 inch rims it came with.