wheel size Vs mpg

[corkgsxr]

mine reads almost bang on. which is weird

You must have the one they made correctly

was heading to dublin tuesday and needed a gps for around dublin. so checked it then. everything iv owned before underead

[Andre]

Mine over-reads by around 7-8% when checked with GPS which is fairly typical.

I always thought it was the GPS either lagging or just being out of sync, not the van?

[corkgsxr]

Mine over-reads by around 7-8% when checked with GPS which is fairly typical.

I always thought it was the GPS either lagging or just being out of sync, not the van?

no speedos arent accurate

a 04 ish yamaha R6 will show 186 mph when doing about 150

[Sling]

My 2.0 hdi also reads smack on.

[steve valentine]

Mine reads bang on since I changed the wheels from 175/65/14 to 185/65/15 :whistle:

[evdama]

Many years ago I was planning a long tour on a mortorcycle and figured changing to a taller tyre would increase the final drive rato therefore reducing the revs in top gear,therefore increasing my mpg.
I didnt figure though with the additional weight of pillion and luggage I would be down-changing much more and the fuel consumption actaully rocketed.

[mikep1973]

I am very tempted to fit the C5 Alloys I have with 195/95/15 tyres on them. The PCD is the same, the centre bore is the same, and the offset is 19 instead of 18mm. I'm not sure if they'll rub though. Does anyone know for sure? It's too cold and wet to mess about if they won't, but the tyres on the C5 are so much better, and it'll be scrapped soon..

I have no idea what effect this will have on speed readings or mpg!

[Drazen_R]

I have two sets on my Berlingo, 175/70 14 /(summer)and 185/65 15 (winter). With summer set speedometer shows about 5 km/h more than real speed, with winter set it is spot on.

185/65 15 comes pretty close to the wheel opening, so I wouldn't put anything bigger than that.

I wonder why dimension 185/65 15 (that have 3.5 % larger diameter than the original 175/70 14) is factory approved, and 185/65 14 that is much closer (just 0.75 % smaller) , is not?

[mikep1973]

I have two sets on my Berlingo, 175/70 14 /(summer)and 185/65 15 (winter). With summer set speedometer shows about 5 km/h more than real speed, with winter set it is spot on.

185/65 15 comes pretty close to the wheel opening, so I wouldn't put anything bigger than that.

I calculate that the 195s are 6mm or thereabouts wider per wheel. I'm sure they'll fit under the arches, it's whether they'll catch on the inside that bothers me.

[steve valentine]

195/65/15 rubbed on my mk2 and required spacers