43 MPG Honda Si (10th gen)
 

Just turned 10,000 miles in my 2018 Honda Civic Si
(1.5 liter 4 cyl turbo)
Averaging 43 MPG over that whole 10,000 stretch
driving like a granny, premium gas, mainly fwy commute
but includes about 2000 city street miles and a few canyon runs

Drove a 2009 Honda Si for 250,000 miles before this
and never got better than 38 MPG over a 10K stretch

Nice economy in a car that will hit 60 in less than 7 seconds, and has no electrical propulsion. Any mods?

Are you driving the CVT or manual transmission?

@herektir
Is also driving a 10th gen Civic, are you still owning the car?

Yes winter brought 90 day avg down but since ownership 15or 16k miles is about 50 mpg with manual transmission 2.0l engine, no mods.

50 mpg is amazing, I'm currently at 37 mpg with the 1.5 and the automatic transmission obviously. To get over 50 mpg I have to drive very slow, speeds below 50 mph are not very save on the Autobahn.

Here are some impressive hypermiling posts from a Civic forum:

excellent

In case you hadn't seen it, honda issued a warranty on your engine for loss of power/oil dilution.

https://www.consumerreports.org/car-...turbo-engines/

I drive the same car and I'm only getting an overall fuel consumption of 38 MPG (6.1 l/100km). Although on the last few fuel tanks I got 43.5 MPG (5.4 l/100km).

Found that picture on the Civic forums, someone took the hypermiling with this car to a new level:

https://ecomodder.com/forum/attachme...1&d=1653989263

Although OP is gone for a long time now. It fits this thread:

this one Hypermiler on the CivicX forum did 700 miles with one single fuel tank. He was averaging 60 MPG without any ecomodding.