Noob need help !

[beZzZ]

Just have a question for every expert here, I realised that whenever I filled up the tank, right afterward my car seems more smooth and powerful in cruising.

Also, I fill my tank with 91 premium gas. Just wondering how come there is a difference, does it mean I need to take it for a tune up or spark plug change?

Just recently done oil change and filter change. Everyone's information are very much appreciated.

[Bluevitz-rs]

Well for starters, you're throwing your money away with the premium gas. The car's designed to run on reg.

And I'm pretty sure it's just a placebo effect, because your adding about 100lbs to the car when you fill it from empty. So the car should actually be slower.

[ozmdd]

Well, you might have some kind of contamination (water?) in your tank if you have a performance change with a full tank. As for the octane, bluevitz is correct: your engine compression is engineered for regular unleaded, and will see no advantage from premium gasoline. Also, most brands of gasoline actually have the same additives (techron, etc) in all grades of their gas, despite what the advertising leads you to believe.

[Billiam]

Yeah...the guys are right. The 1NZ just doesn't have the compression to benefit from premium fuel. You're probably just experiencing the above mentioned "placebo" effect. The only plus at all from using it may be the fact that some brands add additional cleaners and additives to their premium grades. That shouldn't make any difference in a tank or 2 though.

[beZzZ]

Thanks every one, because I heard from a friend saying that 91 is better and cleaner than the 87, and when I use the 91 instead of the 87, I can actually save more fuel.

Will switch it back then. Thanks thanks.

[Bluevitz-rs]

Thanks every one, because I heard from a friend saying that 91 is better and cleaner than the 87, and when I use the 91 instead of the 87, I can actually save more fuel.

Will switch it back then. Thanks thanks.

Yeah, other than the fact that some premium fuels might have more additives and cleaners to their gas, use regular and the money saved can be put towards a bottle of injector cleaner every 6 months or so. Every tank would be a couple of bucks at least.

Also, the 1NZ-FE with a 10.5:1 C/R does have a high enough compression to use 91 or higher octane fuel, but the computer's program limits timing so that is runs on regular 87. I know a guy running a Stand Alone ECU on his N/A Echo and has increased his timing by 10° up to around 42° at the upper end of the RPMs and has gained roughly 7-8hp alone from that and premium gas.

You have to remember that this engine was designed with one thought. Fuel efficiency.

[SamH]

Yeah, other than the fact that some premium fuels might have more additives and cleaners to their gas, use regular and the money saved can be put towards a bottle of injector cleaner every 6 months or so. Every tank would be a couple of bucks at least.

Also, the 1NZ-FE with a 10.5:1 C/R does have a high enough compression to use 91 or higher octane fuel, but the computer's program limits timing so that is runs on regular 87. I know a guy running a Stand Alone ECU on his N/A Echo and has increased his timing by 10° up to around 42° at the upper end of the RPMs and has gained roughly 7-8hp alone from that and premium gas.

You have to remember that this engine was designed with one thought. Fuel efficiency.


Can you get a stand alone ecu for the yaris? should be similar right?

[yarrr]

Can you get a stand alone ecu for the yaris? should be similar right?

probably... for around $500/HP

[beZzZ]

Yeah, other than the fact that some premium fuels might have more additives and cleaners to their gas, use regular and the money saved can be put towards a bottle of injector cleaner every 6 months or so. Every tank would be a couple of bucks at least.

Also, the 1NZ-FE with a 10.5:1 C/R does have a high enough compression to use 91 or higher octane fuel, but the computer's program limits timing so that is runs on regular 87. I know a guy running a Stand Alone ECU on his N/A Echo and has increased his timing by 10° up to around 42° at the upper end of the RPMs and has gained roughly 7-8hp alone from that and premium gas.

You have to remember that this engine was designed with one thought. Fuel efficiency.

I totally agree to your last sentence, Yaris is built for Fuel efficiency. I will definitely go back to 87, save up more to get the injector once in a while.

Anyway, just wondering waht does ECU mean?

[yarrr]

Anyway, just wondering waht does ECU mean?

Engine control unit - http://en.wikipedia.org/wiki/Engine_control_unit

It basically controls everything about how the engine runs, timing, air, fuel, etc. The US yaris ECU thus far is unbreakable/unflashable.

[beZzZ]

Engine control unit - http://en.wikipedia.org/wiki/Engine_control_unit

It basically controls everything about how the engine runs, timing, air, fuel, etc. The US yaris ECU thus far is unbreakable/unflashable.

I see, guess I won't do anything about it, just simply use the 87, save money which I can get more upgrades. :laugh:

[nazier]

i get more miles on the prem, i also find when ever i get a chance i will clean the air filter that also helps the miles add up to the tank, changing spark plugs at every service helps also,

[yarrr]

changing spark plugs at every service helps also,

every service meaning what? I don't know about africa, but our plugs are good for 100,000 and changing them earlier than that is just helping burn a hole in your pocket

[beZzZ]

every service meaning what? I don't know about africa, but our plugs are good for 100,000 and changing them earlier than that is just helping burn a hole in your pocket

I guess every service is a bit too frequent though, even though it will do no harm. I am not sure.

[AlexNet0]

I just changed my spark plugs at about 87k miles, and there was still a little life left in the old ones if I wanted to continue to use them

[cali yaris]

your adding about 100lbs to the car when you fill it from empty.

more like 70, but it doesn't change your point that it's added weight.

[beZzZ]

more like 70, but it doesn't change your point that it's added weight.

Yeah, it doesn't make sense too. Whenever I fill up the tank, the car suppose to be heavier, the acceleration should be sloppy. But to me, the acceleration of mine after the refill get sharper, weird.

[CarBob08]

There is another thing to consider... on a full tank of fuel, you will have "colder" fuel and it will take longer for it to warm up through recirculation and heating in the fuel lines above the engine. So, it is possible to have a slight difference, but generally it shouldn't be noticeable.

As for the higher octane, I have done some extensive studies on my car with both 87 and 92 octane. I get more mpg's with 92, average goes up about 1.0 mpg, but with the cost of the fuel being 20 cents higher, doesn't warrant the extra cost. I still run it though, because I notice that my off-idle throttle response is a touch better and it makes it easier to get the clutch out without chatter on the 92 octane. My 2 cents.