How many mpg did your brand new car gain when broken in?

[Pryme]

Hi all, new here.

We just picked up a couple new mirage's and I've already noticed my city commute( 8mi stop and go) go up from mid 40s to a high the last two days of 52.4 according to my scangauge E. And the car only has 359mi so far.

What typically did you gain by say 3 or 4k miles or more?

Thanks.

[MetroMPG]

Don't know - never had a new car.

Another significant factor is ambient temperature: you will notice efficiency improving as temperature goes up (until you start running the A/C), regardless of how many miles on the car. So, if spring is springing where you live, it's a factor.

Most people who track fuel consumption long-term see a seasonal pattern in the numbers.

PS: welcome to EcoModder.

[Pryme]

Thanks guys. Temps have been pretty steady in the high 30's this week. So as I assumed I can expect my mileage to get even better. Awesome.

MetroMPG you are on mirage forum too eh. Cool.

[Fat Charlie]

My cars never gained anything by being broken in. They all gained as the driver got broken in and learned how to work them properly.

Welcome aboard!

[oldtamiyaphile]

All my cars have improved by quite a bit as they wore in.

My Jeep went from about 14MPG to about 18MPG (no fuel log from new).

My Fiat went from 30MPG in it's first tank to 50MPG currently (still not quite broken in mind you). Expressed in l/100km the first tanks where a dead on linear progression of 0.5l/100km per tank.

My Renault Kangoo went from 30-38MPG. The numbers on that one are a bit cloudy due to payloads, towing and so on. But if you exclude the tanks after I started towing with it, there's a nice gentle upward curve.

Renault Trafic returned 30MPG first tank, and has picked up about 0.8MPG per tank to 33MPG, only working on the 5th tank now.

I put these improvements mostly down to break in (eg as we all know rolling resistance improves as tyres wear - many have reported new tyres= bad MPG), as my Jeep improved all on it's own (pre hypermiler days) and the 20 MPG improvement on the Fiat That car is also shared with a non-hypermiler so again suggest hardware improvements rather than software

I have fuel logs for three cars from new, they all improve over the first several tanks, infact, two are a near perfect linear progression. My used cars show no such trend, as if you can hypermile one car you can pretty much hypermile them all.

[Pryme]

Thanks for the first hand experience guys.

[Frank Lee]

Only new vehicle I've ever had was the F150 and mpgs have only gone down from new in spite of grille block, engine blanket, and mechanical fan delete.

[Daschicken]

My family has had two brand new cars since I started paying attention to fuel economy, but since they weren't MY cars, I didn't track them that much. Too many variables to know for sure.

[Pryme]

Well it could be a combination of my new car breaking in, almost 500mi now, Temps in the low 50s today and me getting used to this car but I recorded another best on my normal drive loop. 64.1mpg avg!! Last night I got a then high of 54.4 avg.

The odd thing is that's off my scangauge E. Which I did enter all the specs correctly. My mirage dash avg shows 49.7 when the scangauge said 64. And it said 47.5 when scangauge said 54?

Sometimes it within 1mpg though.

[Fat Charlie]

Use pump & pencil to calibrate the SG, and once it's on track you can ignore the car's gauge.