[Problem] - Increasing Full Consumption
 

Howdy, fellow 86/FRS/BRZ owners. So here is a some back story on my car:

I jumped onto the 86 family band wagon not so long ago, back in January 2018 when I purchased my lightly used 2015 FRS 6AT from a Local Toyota Dealer. The car had a clear CarProof and only had 15,900 KM on the Odometer, this was a bit odd, but who knows. The dealer was asking $26,000 CAD + HST and all Licensing Magic.

Since I purchased the car in the end of January, beginning of February 2018 we still had sufficient snow weather in Canada. So I also gotten a pair of Snow Tires on Steele Rims. When I gotten the car from the Dealer the Warranty was running at beginning of April, I didn't bother with extended Warranty.

Anyhow, when I picked up the FRS it has 10.2L / 100 Km average. The average would flux between 10.2 - 10.3 L / 100 KM truth out the colder / winter months. I assumed that once Summer kicks in and I put on OEM summers the millage would improve, as I don't run AC often as well.

Well I was bloody wrong, in fact my Average has went to 10.5 > 10.6 > 10.7 and even 10.8 at this point I'm horrified. I mean my driving hasn't changed. At first I though I was being overly aggressive but then I driven 2 full tanks like a Grandpa and the average did not change. I do most City driving, but even so this did not effect my fuel consumption during the Winter months.

I really don't know what's up. The only thing I did to the FRS is muffler delete. Is there a chance the problem is due to the Muffler delete? Or is there some alternative problem with say the ECU or the Fuel Management system? The only thing Toyota did is push an update to the TCU/ECU regarding Idle RPM's, after highway driving and then putting the car into park the RPM's would Flux from 500 to 1000 RPM's to the point it sounded like the engine was about to stall.

So with that said any opinions? I run 91 Octane for most part and I do Full Synthetic oil changes 8,000 - 10,000 KM haven't missed an oil change and have done 2 so far on the car since getting it. As I drive a lot and I'm sitting at 34,000 KM.

Thank you.

see if you can get a scan tool or odb device and look at Long term fuel trims


muffler delete wont effect anything.


the LTFT should be below 10% if its 15-20 you likely have exhaust or intake leak that could effect fuel economy.

Do I need a fancy ODB2 reader? I got AutoLink AL319 one.

Is it still under factory warranty, if so take it to the dealer for a diagnostic.

As far as I'm aware it only has Power Train warranty.

11L/100KM is ~21.4 mpg which is what the car is rated for in the U.S. for city driving, I'd say your fuel economy while unimpressive is not indicative of any major problems.

And here is the explanation why I started to freak out. I had 2 people lately show me (Video) and tell me that there FRS/BRZ get's them 8.8 - 9.6. One guy said the only mod he has is Injen SP Short Ram which increased his fuel economy.

Fuel economy is based on your drive conditions, reset your fuel counter, hop on the freeway late at night with no traffic at 100kmh in sixth gear set cruise control for an hour and beat those numbers by a wide margin.

What you're seeing is normal for stop and go traffic and Toyota rates the damn car at 10.9L/100km for City driving in Canada.