So very recently i replaced my rear tyres from 255/30 runflats to 255/35 non runflats.

the same week i had my timing chain changed and a new clutch fitted.

I used to always get around 45-47 mixed MPG and now it wont go past 38MPG is this coza the extra 5mm on the profile or could this be a thermostat or something? didnt know if just a 5mm difference would make that much of a change, it is on 19's mind

any one got any opinions?

Reset the lie-gauge and report your MPG in the next few days. It will be conclusive if the changes have effected the MPG after a reset

Daz

Reset the lie-gauge and report your MPG in the next few days. It will be conclusive if the changes have effected the MPG after a reset

Daz

Have done mate, twice, still averages 37/38 and today i just did a run from Kent to brighton at 12 in afternoon so no traffic (and no cameras) so not a single stop or even shift down from 5/6th and still only 38, usually thatd be in the 50's. I know my tracking is off which wont help but o go from 44 to 37/38 can this much be down to going from 30 profile to 35?

It will cause some drag but the cold weather would be the biggest factor.