DreaH

2017 Civic EX-T ~17k - recently serviced A1. During the inspection, they advised my radiator was leaking & would replace it. Got it back 6 days go with almost full tank (above 3/4 mark, but not quite F). I had to fill up today with 266 MPT. I put 11.078 gallons in & it estimated at 356 MPT. Thinking it was odd, but maybe just hadn't settled and balanced, I hit the interstate - but the DTE mileage never went up, it only continued to go down. I normally estimate at around 400 miles at fill up and depending on how much highway vs city mileage, I typically get 320-475 miles per tank. Any thoughts what could be causing a sudden drop in MPG?
All the same driving scenarios, as usual....Eco mode is on - overall performance does not seem to be impacted. I am an aggressive driver and I work in the field travelling between many locations, but I've never logged under 300 per tank, even in city only driving.
Thanks for your assistance!

funkypterodacty

Perhaps the ECU needs to be reset ?

DreaH

Thanks - I'll try it.

Farmer Brown

Different gas? From my experience ethanol will kill the gas mileage. Used gas with ethanol on a highway trip (it was all they had at the station) and my mpg was down by about 10mpg.
Looks like the original post is from August. Is this still an issue?

DreaH

Yes, still an issue. 98% of the time I use Shell mid-grade, if I can not use Shell I will only substitute Chevron, also mid-grade, but I have only used Shell for the past 5 months. (not always the same station, but only a different one when I'm in the field travelling & I took the summer off from travel).
Taking in for service this month so I guess i may get an answer then.
Thanks!

FearTheH

iTrader: (5)

I'm a shell fanboy due to the extensive tests and proven results of producing less carbon buildup on intake valves, however, I've read a lot of material showing where shell is not good on turboed vehicles. This is obviously not your problem, just something to think about in the future... make sure your engine air filter is clean, tires are properly inflated and all of that. Did you ever get the factory tune checked to make sure the fuel tables were proper?