Fuel Consumption Spike Since Getting New Tyres.

[NattyFlat6]

Hey guys. I've just bought some nice rims for my 3.0r-b since the stock wheels were looking gross. I've switched from a set of 215/45/R18 Cooper Zeon RS3-G1 to 235/40/R18 Toyo Proxes R888R. Fitted them and got a wheel alignment yesterday, and since then my fuel consumption has gone from ~13L/100 to ~19L/100Kms, mostly city driving. I'm aware these tyres aren't for fuel efficiency but hot damn thats a lot of damage

Only other factor was I went to a different BP to get 98.

Car is at 220,000 ks and I've done heaps of upkeep in the 15,000 I've owned it.

I'm a bit stressed for obvious reasons, so I'm thinking of getting a tune from Kido to see if that helps. but in the meantime should I do the following; swap the serp belt, clean the injectors, clean the MAF Sensor, clean the o2 sensors?

Curious if anyone has had something similar, or has any pointers for me. Appreciate it! (Yes I'm on red P's) https://imgur.com/a/2qkTqVP

[bigBADbenny]

Do you have data logging or any obdii app?
Fuel trims on bank 1 & 2 would be the first thing to check.

[Ric]

That does seem very strange.
I assume you've made sure you don't have excessively low tyre pressure.

[Stifull]

If the tyre pressure is ok and the rolling diameter is ok then it is a bit of a mystery. The rolling diameter of the 215 is 80.4" and the 235s are 79.8" so that is unlikely to make a difference so I would say tyre pressure is the only logical answer. Chuck 40 lb in them and see how the next tank full turns out.

[NattyFlat6]

Do you have data logging or any obdii app?
Fuel trims on bank 1 & 2 would be the first thing to check.

Nah I don't have any obdii tools, will go get a logger and sus the fuel trims. Thanks Ben

[NattyFlat6]

If the tyre pressure is ok and the rolling diameter is ok then it is a bit of a mystery. The rolling diameter of the 215 is 80.4" and the 235s are 79.8" so that is unlikely to make a difference so I would say tyre pressure is the only logical answer. Chuck 40 lb in them and see how the next tank full turns out.

Yeah its super weird. I'll chuck some more pressure in them and see if that helps. Thanks