I need a sanity check from someone with a 2014 es300h. After my last service I noticed that my current mpg display, both on the dash and on the navi display, varies significantly when driving, even on the highway with the cruise control set. I thought it was always fairly constant except when going up or down an grade. Mine goes between 25 & 35 even on level roads with constant acceleration . I would appreciate if someone could confirm what I'm seeing or not. I'm almost positive it was more of constant display instead of going up and down like a yo-yo.
I just had my oil pressure valve replaced too.
Trying to confirm before going back to the dealer.

Thanks

 

A lot of the road that we think of as "level", really are not level at all. They go up or down, very slightly. I live in South Florida -- which is famous for being perfectly flat. But most of the roads here do change elevation -- if only by a few feet per mile. A pedestrian doesn't notice, and the cruise control on a regular car (not a hybrid) barely notices. But, on these hybrids, a small difference in the slope of the road is enough to convince the car to change modes.... Mine often switches to a (mostly battery) mode when going (slightly downhill), and then switches to (mostly engine) when the slope changes to (slightly uphill).

 

I have seen the mpg on my '14ES bounce around also, even on flat highways. Besides hills, it is effected by other variable things like wind, other vehicles draft, AC cycling, etc. I dont recall seeing a 10mpg swing, but your 300h may be different.

 

Are you sure you are looking at the average mpg which does not move much, and not the instant mpg which will be all over the place as you drive.

 

The instantaneous readout is just that, instantaneous and can vary a great deal from moment to moment as Nelexus88 says based on a lot of factors. When I am interested in knowing what's going on, I put a split panel on the nav screen and use the fuel consumption graph which gives you an update every minute - a little more soothing to the sanity of Type A's.

 

I think it's the instantaneous readout. It will read when the engine has no load and is "coasting" where it'll read a higher mpg, or under load to maintain your speed where it'll read a lower mpg. It's normal.

 

+1, my 300h will show 60 on the small info screen when coasting or on the motor generator, anywhere down to about 10 when the gas engine engages, depending on speed, throttle, slope. The OP posted "current", and that's what mine shows. 40+ average after refueling and since reset.

 

Current (instantaneous),average after refueling, and since reset are three different things/display options for the the center dash readout.

The after refueling number will vary widely after you fill up until you get enough miles on the tank to show a better average.