another yaris noob

[SVOboy]

Blocking 1/2 is better than blocking none!

[JanGeo]

I drive places where I can coast for half a mile to a mile without slowing down below the speed limit - actually I go over the speed limit a little. When you get the engine broken in it should use about 0.2 Gallons per hour at idle so if you have a standard you pop it in neutral and coast at 150mpg or more at 30mph. If you can get it to 0.1 GPH then at 30mph you get 300mpg! but it only seems to do that low burn rate once in a while - usually the idle is a little faster than the 650rpm 0.1gph rate like in the 890rpm 0.2gph for some reason.

[JanGeo]

Originally Posted by SVOboy

This picture:

Tells a different story about engine temperatures and fuel trim correction values.

That doesn't show a Scion engine graph and doesn't show high temps above 200F. I tell you what - when it started to get a little hot under the hood last week sitting in traffic for 45 minutes it did not want to cool off. And the AC performance in the Scion is only good when the entire condensor is cooled off - yeah it works ok if it gets hot but then the radiator fan runs even if the engine is cool and that all takes more power and fuel like 33-50% more sitting at idle.
I also asked Miro at Synlube about raising the engine temp and he did not recommend it. Keep in mind that cold air ala cold engine NEEDS a richer injector because teh cold air is more dense. These Yaris / Scion engines have a heated throttle body which would affect the air temperature thus the air fuel mixture - in the end the oxygen sensor conpensates anyway - except in the extreem engine temperature condition from what I understand.

[JanGeo]

Originally Posted by MetroMPG

Yup. As a VERY conservative start, I'd at least block the area that's not directly in front a radiator. But the block, if not done in front of the grille, would have to go directly up against its "back" on the inside. But that'll just trap bugs 'n' stuff, won't it?

Any air you can keep from going through the grille and ultimately exiting under the car is better off going over/around the outside.

That I can agree with by diverting the air around but looking at it - it looks pretty small to begin with anyway - most of my front "grill" that looks like loovers is solid and does not pass air in fact diverts to the side of the hood to the head lights instead of over it. I also noticed that drops of rain water on the hood just sits there when driving down the road at 35-40 mph. Another thing is that air entering the grill on the right side actually goes into the right front wheel well area - not sure why but it probably helps cool the brakes?

[JanGeo]

Originally Posted by ketel0ne

Here is the best front end shot I got so far. Ignore the second set of 30 day plates The pic is huge.

http://i66.typepad.com/mpg_digest/yaris/IMG_3114.jpg

Seems to have a nice belly pan already too!

[MetroMPG]

Without actually seeing the car, all I can say is I'd block any openings that aren't in front of the radiator.

[Silveredwings]

Metro - 3% is a decent improvement for such a small change (grill block).

[MetroMPG]

True, but relatively speaking, I think my car has a much "worse" grille than the Yaris, and so had more room for improvement. I've tried to check out a few Yarii in traffic since this thread started, and they don't appear to have excessive openings.

GM stylists went overboard with the openings on the front of my car. It's actually got more open grille area than the front of a 97 Camry - a car with double the weight and 2.5x the engine displacement!

[AlexK]

Hi schmeep,
I have a yaris sedan with manual trans. When I got my scangauge the most important thing I learned is you burn less fuel by idling than engine braking. Engine braking also dissipates kinetic energy, which you could be using to coast further. I stopped engine braking and now I will put it in neutral and coast (engine idling) up to stoplights and through neighborhoods. It makes a huge difference in FE and is easy to get in the habit.
So far I haven't dropped below 41 mpg over 4 fillups. The first few fillups were highway miles but the last two were all city driving but "city" to me means 50mph with stoplights every 1/2 mile or so and mild traffic.

[schmeep]

hey alex, how do you like the yaris?

my driving usually consists of small city trips of 15 minutes or less with moderate to heavy traffic, with the odd 40mile trip once a week, so my drives are probably the worst type for fe.
i have also tried to stop engine braking, but i have been driving like that since i started driving and it is a really difficult habit to break, but i'll have to try a bit harder.

check out my gaslog, when the yaris was fairly new, i was getting poor fe, but it has improved quite a bit recently. but i'm hoping for better.