Does Gas Mileage Increase After 1st Oil Change?

[ChilliwackGuy]

I bought a new 2010 Yaris 5 Dr Hatch (Auto) on June 5, 10 - in Chilliwack BC, Canada. So far - I have been getting about 6.1 - 7.2 L per 100 KMs mileage. I usually drive it about 200-250KMs a day during my commute (90% Highway / 10% City) - and I fill it to the 2nd click - using 87 rated Cost-Co gas in Abbotsford BC.

My salesperson said that I can expect my mileage to get better after the 1st oil change - which is scheduled for 8000KM. He said that because it's a new car - with a new engine - there will be a lot of engine / gear debris - and once that's all removed - my gas mileage will increase.

Is that true? Does the gas mileage increase after the 1st oil change? (I sure hope it does as my current Yaris mileage isn't that much better than what I was getting using my wife's 09 Rav 4 - 4WD Limited (Auto).)

Thanks!

[RedRide]

A very general rule of thumb is that gas milage peaks at about 10k miles and then, slowly goes down over the life of the engine.

So yeah, it will probably increase a bit after the first oil change

[OtownYaris]

I would say mileage would get better after the first oil change.
I noticed I got really good mileage when I first got my Yaris and then shortly after Florida switched over to 10% ethanol gas and I was lucky to get 280 miles on a tank before the gauge went down to 2 bars. But, oddly I've noticed my gas mileage get a tad bit better since my Yaris hit around 30K miles. It's got 36K miles now and I was lucky to find a gas station out in the middle of nowhere that still carries non-ethanol gas (for a higher price of course) and that helped mileage even further. At my 35K oil change I put in Mobil 1 0W-30 and I'm not sure if it has helped gas mileage since my Wife mostly drives it now (I got a Cube). The engine seems a little quieter and less shakey since I switched over to Mobil 1 though. I'll always love the Yaris for it's simplicity.

[ChilliwackGuy]

Wow! Thanks for the replys - I'll convert the miles to KM's and wait patiently to see what happens with my Yaris.

[frog13]

Just as the sales person said...worn engine debris.Change the oil and filter at least once prior to the recommended schedule.....get the "debris" out of there.Folks worry too much about oil shear points for the ENGINE......the transmission is where "shear" oil hell is(gears meshing together,etc.).:eyebulge:

Synthetic oil is not more "slick"...it's more tolerant/stable during use.

[ChilliwackGuy]

Great - thanks for the info frog13!

[ChilliwackGuy]

An Update As Of 26/7/10:

Yippee! My Yaris turned 8000 KM - so time for it's 1st Oil Change! Actually - it will be about 9300 KMs old on Saturday - 8AM - July 31, 2010 - which is when the appointment is scheduled for.

I was given 2 options:

a) $44.99 CDN + HST for Standard Fossil Fuel Oil Change

b) $54.95 CDN + HST for TGMO OW20 Oil Change

I selected "b" - TGMO OW20 - only the best for my 2010 Yaris HB - Oh Yeah!

Anyway - I will be sure to let everyone know if my gas mileage improves AFTER the 1st oil change.

[Toppers]

A very general rule of thumb is that gas milage peaks at about 10k miles and then, slowly goes down over the life of the engine.

So yeah, it will probably increase a bit after the first oil change

Sorry to burst your bubble this is not true. I get 37 MPG Highway in a 10 year old Honda Civic with 140k miles. It has gone up in the last 40k, not gotten worse. Gas mileage is more determined by how the engine was broken in the first 10-20k miles more than anything, and all the contact surfaces seated / mated. Oil has nothing to do with it.

That's why you should never baby an engine during break in, you really want things to seat well for a life long reliable engine that doesn't burn oil and gets good mileage. "Drive it like you stole it".

[sickpuppy1]

My "old" 2001 Civic sedan was still doing 38 mpg on the highway at 144,000 miles when I sold it to my son. On the road trips to and from California, he got very similar mileage too. (not as good since he was in a hurry to get the 26hr trip over with, go figure)
Break in has a lot to do with longevity, and while I got it with 36k on it, I know the original owner and it was not babied around....

[ChilliwackGuy]

I totally agree with the "drive it like you stole it" slogan - a cheap commuter car is meant to be driven - not babied. My reason behind posting the initial thread was that where I live - new Yaris drivers are promised fantastic mileage rates - after the 1st oil change. (only time will tell - LOL!)

[ChilliwackGuy]

OK - I went for the 0W - 20 oil change last Saturday - July 31, 10 - and so far have averaged 6.2 L / 100 KM - but that's only after 2 tanks - I'll keep track and post after a week or so.

My sales rep told me I should see results (imcrease in mileage) within a week of the 1st ever oil change.

PLS NOTE - I'm not going to get PO-ed if it doesn't happen - I enjoy my Yaris - but it does help confirm/refute an urban myth - and gives me yet another esoteric fact to mention to fellow Yaris owners. LOL!