Fuel Economy

[keesue]

My first tank was actually 35.8/mpg and the second tank is 35.9/mpg. This is with two people car-commuting with me, 90% freeway, 65mph average with some inevitable stop and go. I am completely amazed at this. This is coming from a car that averaged 19/mpg and which required premium fuel. The savings is tremendous. I am pleased to say the least.

[tds12]

First 4000 miles 39.5 MPG. Manual transmission. 80% highway, 60 MPH.
Follow other vehicles when possible...My scanguage indicates up to 10 MGP improvement when following a large truck (6 car lengths).

[swng]

Originally Posted by tds12

........Follow other vehicles when possible...My scanguage indicates up to 10 MGP improvement when following a large truck (6 car lengths).

This is very useful information for people who are without the benefit of a scanguage/trip computer like me.
Thanks for sharing!

[spkrman]

now we'll have a forum of semi tailgaters... :)

[swng]

What a quick mind and good sense of humor!
Surely we have to drive safely. In fact, following a truck can reduce drag but following too closely may also render it difficult to judge the traffic conditions ahead, which may lead to abrupt stopping and heavy braking (if not an accident) and thus waste of fuel. I am sure the member who just shared his experience never intended to recommend following too closely. I think he just mentioned his scangauge observatons for academic interest. IMHO, we should always keep at least a two-second distance from the car in front. An even longer distance should be in order in unfavorable conditions.
This thread is useful because of all of you who contribute to it. Please visit and post frequently.

[BMGYaris]

yea, i have read somewhere somethinga bout a car length for ever 10 mph, but whatever. Anyway, we should all write mythbusters. It would be interesting to see exactly what distances behind a big truck change mpg and how much per distance. My initial thoughts are that if you drive far enough behind the truck to have decent visibility, then there wouldnt be too much advantage as the wind would have...i dont know..repositioned?:) anyway, lets send some emails to mythubusters with this one.

[spkrman]

it would also be uncomfortable for the truck driver to have a lil car that he probably can't see behind him. Maybe the biggest gain in MPG you can get is a CB radio? :)

[swng]

Just for academic discussion, and don't do it a home. Professionals do agree that following a big truck in front can save fuel. Please read this review (to save time, please go direct to the paragraphs under the sub-heading "Fuel economy run"):

http://autos.msn.com/research/vip/jo...&model=E-Class

Here is a quotation from that web page:

"We used a different strategy when we got on the highway, though. We sought to draft behind large vehicles—in actuality, tucking closely behind a pickup truck towing a camper, and later getting behind a semi. But this meant we couldn't see much ahead of us, and we were required to match the speed of the bigger vehicle directly in front."

Note in particular that there are comments about the disadvantages of so doing in the same paragraph. For daily driving, I suggest safety first.

More discussions in this and other aspects of fuel economy are welcome, friends!

[ECHOKnight2000]

I read that following a truck closely you can coast but its very ideal conditions, meaning the draft of the truck pulls the car of course bigger cars it would be harder but for the sake of the Yaris...obviously this is dangerous. There is a point where the truck's draft creates a turbulance so the car is shaking, sort of like a jet stream (not saying it is just a comparison). Sorry I'm not to knowledgable on the techincal words. Anyway you have to follow really close and for the sake of mpg, no not worth it, you're asking for trouble or a death sentence. Just my .02

[tds12]

You don't need to be real close to see a difference in the scanguage MPG. 6-10 lengths. This is way farther back than typical freeway driving in Seattle.
Also it doesn't have to be a large truck any vehicle that disturbs the air in front of the Yaris. Larger vehicles work better but it is a noticable decrease following any vehicle.

[spkrman]

scanguage is definitely on my list of things to get... now a very long and expensive list!

[nsmitchell]

Holding steady at 31mpg. I am not really driving for mileage. Lots of lights, lots of stomping on the gas. ;) I am still waiting to take a good long road trip to check out maximum mileage. Hopefully around 40 something.

[lispat]

Originally Posted by yariman

The Yaris engine is designed to run on the fuel that is recomended in your manual. ( different parts of the world ) Unless you can change the timing and fuel maps etc. it won't run any better on a higher octane fuel. There are more additives in better fuels such as Chevron has more Techron in their higher graded fuels.

I tried higher octane in my Tacoma, it doesn't like it, I would stay with what Toyota says, they have a lot of expertise. If not we'd be driving something else. Ooooh, I wouldn't like that.

[spkrman]

premium did fine in my yaris, no major gain anywhere though.

[nsmitchell]

Originally Posted by spkrman

premium did fine in my yaris, no major gain anywhere though.

Premium gas is ONLY for high compression engines. To put it in your Yaris is truly wasting money. In the following article, he even mentions "The Family Toyota".

http://www.straightdope.com/columns/041008.html

[fearturtle44]

I would recommend a fuel injector cleaner every 7500 miles. Just put in an empty tank prior to fill.

Kevin

[keesue]

I concur with the statement: "Premium is for high compression engines". The Yaris is not a high compresson engine and does not require premium. It does not suffer detonation which is the sign of an octane level insufficient to support fuel burn over explosion (detonation). It is a complete waste of money. As to fuel system cleaners, if one exclusively uses a high quality fuel, such as Chevron with Techron, it is less of a requirement. Most new vehicle certifications for emissions and fuel efficiency ratings are performed using Chevron (by the way). The difference in cost between grades can be significantly offset by using a fuel system cleaner when using lower grade fuel.

[bigsky2]

Right now my mileage is approximately 7.5~7.9L per 100KM.

I usually fill up with two or three bars remaining and calculate the mileage from the amount I travelled on the trip and the amount of gas that filled up the tank.

I did run the gauge to the last bar last week, and I filled up. It was about 38 litres or so and my trip was about 500 km. Works out to about 7.6L per 100km.

Not too shabby, but not the best either. I don't think I can achieve 6.9L per 100KM (stated City mileage by Toyota) unless I turn my car back into its stock form.