Gas mileage keeps getting better during break-in?

I took delivery of my ORO 4/6/23. I am just now getting to around 800 miles on vehicle. I only put about 10,000 miles per year on my 3rd vehicle since I use it for hunting and road trips primarily. I drive a beater 2008 Accord around running errands, etc and I’m retired. My gas mileage on short trips non-Highway is routinely > 21.5 mph sometimes hitting 23, not driving on the highway. These trips are suburb driving where stop lights may be 1-2 miles apart, not City blocks. I am confirming the accuracy of the vehicle ECO data by calculating the tank average mpg when filling up. The first tank was about 19.5 mpg including 40% highway miles. The 2nd tank was around 21. I drive easy on the vehicle. I don’t race to the speed limit and I don’t wear out brakes stopping fast. Is it possible as the engine “wears in” the efficiency rises? I did not get any better mileage on my 2016 Tacoma TRDOR with the 3.5 V6. I did not expect 19 mpg ever on a tank average when bought the 4 Runner.

 

It seems pretty typical for the fuel economy to improve over the first few thousand miles. Mine did.

 

Sounds plausible, everything starts to loosen up. Just curious what octane are you using?

 

Using 87 Octane

 

Gas doesn't matter much, top tier ideally. But its pretty typical for the fuel economy to improve after break in.

 

You'll see a slight rise from new, and then a huge decline when you add your lift, tires, roof rack, bumpers, sliders, second battery, sleeping platform, roof lights, recovery gear, medical kit, food, water, and wife (she comes with five days of clothes for a weekend trip).

 

Yeah, after break-in I was getting 19-21. Now with all the mods I get ~15-16. lol

 

I bought a 2023 in October 2022 and the mpg improved after a couple months. I average around 19.5 to 21 mpg every tank, all non-highway miles. Enjoy.

 

Mine followed the exact same trajectory. After several thousand it slowly keeps increasing to what I think is normal.

 

Did a 400 mile round trip on mountain highways to a favorite retreat last weekend and averaged 22.5 mpg at 70 mph which is best I've seen on this truck and what I feel is good for a 10 year old 4runner with close to 140K miles. Replaced plugs with OEM last month and Michelin Defender tires have consistently given good fuel economy on several vehicles we've owned. Mobil 1 ESP 5W30 engine oil and Red Line 80W140 gear oil in differential don't seem to be decreasing fuel economy at all.

 

Dang, Those are respectable stats right there!

 

I think it has a lot to do with driving style. I'm a light foot, too, and will average 22+ in the summer (winter gas is a real thing). As for the improvement you're seeing, the computer gets a bigger sample to measure as the miles increase. If you reset it, the numbers will be off one way or the other for a while.

 

my 2019 SR5 has about 73k on the odometer. if I ever got more than 22 mpg, I'd assume the computer was broken.

 

With 6300 miles on the odometer now my 2022 TRD Off-Road is averaging right around 22 mpg since new. But then where I live I don't have to put up with many stop signs/stop lights, so no stop and go driving which is what kills fuel mileage. Took a little trip last week mostly on good dirt roads so I was driving 40-50 mph most of the time. Here's my display reading after 270 miles so the 4Runner can do well in certain conditions.

 

My car keeps Showing 17-18 mpg. That hasn’t changed since I bought 3 months ago.

 

That return....., Is right respectable.

 

I usually gained 1/2 mile per gallon every 80-100k.I don't know if they ever really break in

 

That's good to hear. I'm on my second tank of my '23 and the first tank which was from the dealer I averaged maybe 16.5 but this was primarily stop and go around town/school pickup, etc. I'm doing a little better now with the second tank. The gas station chain near us is running some sort of special where all of the grades of E10 gas are the same price if you're a member, so I got Super for the second tank since it was the same price as Regular, lol.

 

I had a 92 Camry 4cyl and 4 wheel disc brakes which was rare. It had 235k on it and it was the most free running engine. It would wind up so fast. I never seen another Toyota engine run so free. I could put wife and 3 kids, trunk full and them holding some, run 85mph to Indianapolis and get 36mpg. It still amazes me. My Tundra I gained mileage every 80-100k. That said I would never expect that in 4runner. I try to drive smart when racing to next red light. I use 4th in town if I'm not running over 55-60. Usually more like 35-45mph and it doesn't affect my mileage. It's a little better on brakes and less shifting. 24mpg is best I hope gotten on long steady drive. Usually 19mpg around town.

 

Lol. Actually, a lift didn't decrease my mileage in my daily driving at all. Neither did the roof rack. Weight doesn't inherently decrease your mileage, so long as your acceleration decreases. Force = Mass x Acceleration

Technically, you may have a little more kinetic friction, being heavier, but I couldn't tell you how much that matters. That and wind resistance would be the factor at a steady speed. Just go slower and mileage will stay respectable.

*Insert something about unsprung mass.

 

My mileage actually decreased after break-in. Just hit 5k miles on my way in to work this morning. We used to get 20-21 MPGs, but now we're at 16-17.

 

Just turned 10,000 miles on my 2022 on a trip I had to make this past Saturday. All but about 50 miles of this was on dirt roads so the average speed was pretty low but still, this is about 8 mpg better than I would have gotten if I'd made the trip in my Jeep!

 

Did your driving habits change? Did you add a roof rack, or other modifications?

Aside from that, colder weather ruins fuel economy, between winter blend gas, longer warmup time, increased wind resistance, etc.

 

Firm negative on roof rack or anything. Could definitely be the colder weather and winter blend gas, didn't even think of that lol

 

Hopefully it's the weather and the gas!

 

Exactly what happened to me. This past weekend I hit the 2k mile mark and I was averaging 22 MPGs.

Not only that, but the engine feels a hell of a lot more peppy than the break-in period before the 1000 miles.