Taking my first road trip in our 2025 RX350. First 150 miles is tollway the rest is 4 lane and 2 lane country roads. Is it better to drive in Eco or Normal for better gas mileage?

 

I just came back from a 2,220 mile road trip in my RX450h+. I used ECO only on the long stretches of hwy in the middle of nowhere.

I don't have enough experience to tell you how it affected the MPG but I can tell you that when the cruise is on you can't tell. Also, it was over 100 degrees for most of the trip and the air worked great in ECO mode.

My mileage on the way back from San Diego to Colorado was somewhere between 36-37. I screwed up the trip history on the way there but I am assuming it was somewhat higher do to elevation changes. It was 42.5 from Colorado over the Rockys and down the other side before I cleared the history on accident.

 

We're on our 3rd 2k+ trip this Summer in our RX350 Premium +. Interstates, back road highways, scenic drives, etc; all the touristy driving stuff. Averaging 30mpg in Normal, sometimes switching to Sport on the cooler roads. In our '23 RX the ECO mode always seems less responsive. Consequently, we never use it.

 

I live in Southern California - lots of hills and topography. I keep my 2023 ICE turbo in Eco all the time. I've never had a loss for power or had it affect the climate control (and I use the AC a lot in SoCal). My average mileage every tank is 25-26 MPG.

 

At highway cruising, I doubt the mode really matters for fuel efficiency.

 

ECO IS less responsive. I don’t find it very noticeable because I’m not into jackrabbit starts or have the need to jump quickly into traffic very often. If I do need a little boost, my right side touch control just takes a minor movement to shift me into SPORT.

 

On my last road trip of about 550 miles in my Premium +, the average mpg was about 28 in normal mode. Not bad at all, especially when I got a healthy discount (vs the hybrid) for the purchase.

 

if you hypermile, then you’d be better off in normal mode. The lag in ECO slows your acceleration, which tends to decrease your speed. I can get 39.8mpg in my RX350H driving the hills around Pittsburgh. Im sure on flat terrain, I’d be well into 40+mpg.

 

Human 'beans' will tend to maintain comfort levels...meaning that if throttle response is decreased, they will just press it down harder.

This is like the drivers who drive 60 in a 70 area, but still go 60 when the urban speed limit drops to 55....

 

I recently drove my RX450h+ from Sacramento to San Diego and back with AC on and in eco mode. I began with a fully charged battery and in hybrid mode. When I reached San Diego, the battery was down only by 5 miles (close to a full charge), but gas mileage was just over 43 mpg. I used the rest of the battery charge in San Diego. Driving back in hybrid mode (no ev battery charge left), gas mileage was only 37 mpg. Average speed was 70 mph both ways (Hwy 99 down and I5 back).