Texasdeere

Ok the last tank 400+ miles was 25 city & highway mix. I don't think I will do much better than that until I take a long highway trip somewhere.

RX in NC

^^ Agreed. Anyone averaging 25 mpg in mixed driving in a 3rd generation RX350 is doing extremely well indeed.

RVH

Regular or high test?

I've used nothing but regular gas for 12-yrs and never had an issue. Highway I get 26.5 or so at 65mph and 25 mpg at 75. I find that speed is a big deal.

Texasdeere

I use the regular or 87 Octane. I think one of the big factors in my mileage are the top speeds along my route are only 55 to 60 mph.

Your highway mileage numbers are what I would expect

paparon60

I only get 10 mpg ..

RX in NC

My 1999 Ram 1500 pickup with the big 5.9-liter V8 gets 14 to 16 mpg depending upon speed and terrain. If you are getting just 10 mpg in a 3.5-liter V6 RX, you definitely have some issues. How old are your spark plugs and air filter (and are they the correct ones)? Have you ever cleaned your mass air flow sensor? What are your tire pressures? Are you hauling around excessive weight? I would spend some time figuring out what is wrong.

jmazel

Attached is mileage log and chart for my 2013 vehicle. The data cover 100k miles, including multiple trips from FL to PA, a 10k cross-country trip, and pulling a trailer loaded with a motorcycle. Real world data.

YMMV.

intermec

well organized log. Thanks.

My wife's 2010 AWD gets about 18.9mpg based on the car's info. In general, she refilled right about 280miles after refill with around 30miles to empty to go.

sunnyside

I have a 2014 RX 350 FWD. The milage has been pretty consistent over the 86,000 miles that are on it now. Ranges from 22-25 depending on where we drive. Always on 87 octane gas. It is pretty clear to me that something was changed with the 2013 engine. This car is now just use close to home. I bought a Ford F150 hybrid last year to tow a travel trailer and it gets 24-28 on regular gas. We now travel in it. The wife likes to sit up high and it has a lot of tech. Neither of us likes the newer RX style. We expect to keep this one till it drops.

PHOUND5

I used to keep detailed fuel logs for my wife's 2010.The biggest improvement we made was removing the roof rails. Car was much quieter on the highway and highway mileage on cruise moved up a bit 0.7 mpg. on long trips

We live in BC with lots of mountains and hills so the car is never loafing along like it in the prairies, and 50 % of the year we have 4 snow tires on the car. Total mileage since new 97.000 kms or about 61,000 miles.

The mechanics at the dealership are always asking to buy her car.

RX in NC

After removing the roof rails, what did you use to plug the holes in the roof?

WolfyLS460

MPG: I only get high 20's on open roads that are level or downhill. In city I get 19-22.

Oil Change: full synthetic every 6000 miles.

Gas: 87 regular (ARCO, Mobile, Chevron, whatever), add a can of Techron at every oil change. High-octane premium gas is only needed for high-compression engines, not the RX non-hybrid V6. I have used both regular and premium gas, and saw absolutely no difference.

OnlyMe

All of a sudden, I am getting 7.5 KM/Litre (17 MPG) on my 2013 RX350. Any ideas? TIA.

OnlyMe

I have been keeping track of my mileage. I had been getting 11.2 to 13.7 km/L all along. What makes this one hard to swallow is that all kilometers in this particular calculation are highway miles driven at an average of 66 MPH. According to the manufacturer, I should be getting 24 MPG or 10.2 Km/L. So, what am I missing? Is there something I need to do in case something is not right with the engine? Mind you, the temperature outside was around -11 degrees F.

MacCat

As your car engine gets older, the gas milage will go down.
Many things can contribute to that.
Depending on the age of your car, most aren't worth getting fixed.
If it's under 100,000 miles, I think it's worth getting the engine checked out.

• Valves get dirty and they can be cleaned.
• Fuel injectors get clogged up, especially if you use fuel from unknown sources and change brands a lot.
• Air filters are easy to change out and sometimes that helps, too.
• Very cold outside temperature can also affect milage.

I drive a 2010 RX350 with 120,000 miles on it.
I'm retired now, so I drive less than 7,000 miles a year.
City 18 mpg
Highway 20 mpg
92 octane
I get it serviced once a year - oil change and tire rotation.

I absolutely love the car. It's trouble free, reliable, comfortable and safe.
It was a lease car I bought with 24,000 miles on it and it cost me $30,000
I have never bought a new car - ever.