acarapella

Hi. My 2003 es300 with 63,700 miles is getting terrible mileage. For example, on flat road, at 75mph the instantaneous (or the average mpg if I reset it and drive a while) shows 18-19 mpg. If I go 60 it's better, like 26, but a days driving mostly highway averages 23 in 55mpg zones.

I got the car Monday. It had half a tank. I filled it once it got near e with 87 octane. Once it got to half again, I filled from half to full with 93. The old owner probly used premium. I know see paid big bucks to have the dealer do the 60,000 maintenance.

There is no check engine light lit so no codes to pull. What could it be?

Oro

You are computing the mileage from the very accurate odometer (assuming stock wheel size), and then dividing it by the gallons pumped as measured by the regulated and inspected fuel meter at the gas station, right? Computers do their own thing based on highly variable and error-prone inputs and aren't very often correct. I get vastly better mileage than my computer says - I use miles driven/gas in to figure it. The computer isn't close.

If you are pumping ethanol in it, and running 60/65mph, I would expect a up to a 10% hit on mpg and thus about 26 mph freeway.

We have an 02 3.0l and i've played lots of games measuring mileage loaded, unloaded, mixed, highway, summer, fall, etc. The car is in perfect tune and constantly maintained. i can get 29.5/30/mpg with driver alone at a steady 55/60mph on flat roads and everything falls off from there. This is actual computed MPG on numerous fills (any one fill is irrelevant as pumps deliver different top-off/stop points). The computer never is accurate.

acarapella

Wow, so 20 miles per gallon at 75 mph is what I should expect? That's insane. I was counting on this car is mechanical similarity to my wife's Solara V6. She drives somewhere in between mild and aggressive and averages, averages 28. One time on a trip from south Florida to North West New York State he averaged 36. Of course she was following the truck I was driving at 60 mph with the Backdraft, but she had a full car.

So it's not possible that something could be mechanically wrong with the car that an engine light is not indicating? It doesn't feel to have any resistance one rolling. Also, what octane did you use

hypervish

No, that's not what you should expect.

He's asking you how you calculated that average... Did you read it off the computer? or Hand calculate it?

I don't primarily drive the ES, so I don't have much mpg stats unlike my RX. However, the one road trip I did take in it at 78 mph (with occasional 85 mph spurts) gave me 28 mpg. I was shocked, I was expecting much closer to 25 considering the speeds I was traveling. Great mileage for what it is.

acarapella

Well I was going bye the computer cause the one in our solara v6 has been accurate over 65,000 miles but I will do it the old fashion way.

So say it is just bad, how could i figure it out? Tires are inflated and there is no drag... No engine light. I can't adjust the air fuel mix or timing like in my 1950 Chevy so where do I even start

iWorstLuck

My computer was pretty accurate. 03 es300, about 300 miles a tank (all city), 16 gallons, around 18-19 mpg. No cel, tires also inflated

PFB

Since you just got the car, it would be a good idea to shut off the car, disconnect the battery for a few minutes, and reconnect the battery back.

This will reset the engine computer, and allow it to relearn and adapt to YOUR driving habits instead of to the previous owner's.

Drive it for at least two tankfulls the way you would normally drive it and see if your milage improves.

It's always best to retrieve, note, and reset, any codes that may have been stored in memory prior to disconnecting the battery.

Phil

acarapella

The battery was serviced right before I got it. I can tell it was right before cause the moonroof needed to be cycled before the auto open and close worked.


I am wondering if anyone has any suggestions about what can cause bad gas mileage outside of drag on the wheels which I have eliminated, and a engine control issue which a check engine light would indicate. I can say this: my exhaust ticks like its cooling when I park the car. Maybe something is off kilter as far as air fuel or timing. But I thought an engine light would show that,


If this was a classic car, I would clean or replace my plugs, check the gap of my points, adjust timing or air fuel. Perhaps disassemble and clean the carburetor. None of these things are my job with the 1mz. The computer does them all thousands of times per second. So, with no check engine light of major symptoms , what can hurt mileage?

Norbecke

Honestly I get. 1-2 mpg better than the comp says. I calculate manually by miles driven to gallons used. And I have an 05 es330.

acarapella

It's gotten a little better since going with 93 octane. 24 average. I can get 28-29 on an expressway trip. Still I think it's bad. My wife's 3mz solara gets 27-28 average over several months of her not resetting the meter.

Whatever. It's a nice car and I like it. I just wish there was things I could investigate to see if I could improve it but without a code I am afraid I don't know where to start

PFB

I really think there is nothing wrong with your car. You'll see better milage when the spring fuel formulation returns to the pumps, and it gets warmer outside.

No need to spend extra money on higher octane fuel than recomended. Waste of money.

speedkar9

I agree with the rest, don't follow what mileage your computer gives, especially the instantaneous mileage.

I've found the instantaneous gas mileage to change dramatically with the slightest change in throttle input, road incline or head wind.

Take the total amount you've filled up the tank and divide by the mileage to get your actual fuel consumption. Eyeballing the fuel gauge isn't accurate either (I find there's still ~7L in the tank even when the range reads 0km).

When comparing cars, remember the 3MZ Solara is a lighter car with a more powerful (and supposedly more efficient) engine. Between my 1MZ Solara and 3MZ Lexus I get the exact same fuel economy per tank.

I'm averaging 17 MPG (13.5 L / 100km) with a 75% city/ 25% highway commute, in cold Canadian weather.

DaveGS4

iTrader: (2)

Don't forget to also check your tire inflation. Can make a noticeable difference

iWorstLuck

Same here but I've accepted the fact. I was hoping to get around 21/22 city when I fist got it

acarapella

Just wanted to let everybody know I use the odometer to figure out my gas mileage, and you were alright. The computer is wrong. 28.18 miles per gallon