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Discussion Starter · #1 ·
anyone else getting really random displays? normally a full tank'll display around 420 miles for me, but there're times (like this past fill up) the range'll be about 390 miles. same shell gas station, always at night, always 89 octane. i can understand a 10 mile difference, but a whole 30? i mean granted, the computer's calculation might be a little whack, but to have completely different range of miles left on a full tank seems a bit odd.
 

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Mine acts funny like that sometimes but it seems to 'settle' after a few miles of driving....I still end up getting 400+ per tank....wouldn't hurt to take it up with the dealer service department while that warranty is golden....
 

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Mine is rather random as well. I honestly don't give those readings much thought as they are seldom accurate. My wife's Toyota DTE reading is similar and is based on the average mileage of the previous tank. However, it changes as you drive and over estimates the distance by at least 70 miles. I noticed on the my recent road trip in my Mazda, that it too was off by 50 miles or more too.

Since the average MPG is overly optimistic, and the instantaneous MPG is rather random, I don't give the DTE much credit, and rarely view the trip computer screens. Of all the cars I driven over the years, VW and BMW were the only ones who came even close to being accurate.
 

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could it seem like an over estimation because of the reserve fuel? maybe it includes the reserve fuel in the range calculation
On the Mazda, I don't know. I haven't run it that low and haven't had any chances to truly experiment.

The problem with the Toyota is two fold.
1) It's based at the start on previous tank average economy
2) You can be completly out of gas and still show miles to go.

I've never run the Toyota out of gas, but by doing the math and seeing how much I put in the car, kowing how much the tank holds, and the mileage I was getting I knew I would never get the range the display was showing. I can be at 1/4 tank and the DTE will tell me I have 120 miles. However, 30 miles later the light comes on and I know based on what is left in the tank, I have about 15~20 miles at most before I'd be in trouble.
 

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Discussion Starter · #11 ·
i usually use the same pump at the same station too. i dunno, it just happens sometimes. the shitty thing is, i actually have less gas. i'll bring it up at the dealership and hopefully get an answer, just in case this happens to anyone else.
 

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A.K.A. - Zuma2010
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yeah, I usually get about 420-430 on the range after I fill up with Mid-Grade Chevron Or Shell as well. Only once did it read 390. But yeah, it is based on the average. I periodically reset the averages, so that may be another thing to try.
 

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A.K.A. - Zuma2010
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Mind if I ask why?
why i use it as opposed to premium, or as opposed to regular? if why i use it as opposed tyo regular, cleaner gas means longer life of the engine components, am
nd a little added performance... And ive always been a midgrade kind of guy...but im considering movin up to premium...
 

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if why i use it as opposed to regular, cleaner gas means longer life of the engine components, and a little added performance... And ive always been a midgrade kind of guy...but im considering movin up to premium...
Not trying to start anything or be a douche, but that statement is not true at all. But wait! All of the race teams use high octane fuel, so that means high octance fuel = high performance, right? Not exactly. Octane is essentially a measure of how easily a fuel will combust when put under pressure. The higher the octane, the higher the pressure it takes to combust the fuel. This also means that it is harder to burn the fuel. High performance engines run extremely high compression ratios which require high octane fuel so that it does not detonate. They get more power because of the higher compression ratios, not because of the higher octane fuel.

Since our engines can be run on 87 octane without detonating, they should be run on 87 octane (as long as it is not crappy quality). Since 87 burns easier, it will provide more energy per unit volume. So you are actually getting less performance from running 89.
 

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A.K.A. - Zuma2010
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Not trying to start anything or be a douche, but that statement is not true at all. But wait! All of the race teams use high octane fuel, so that means high octance fuel = high performance, right? Not exactly. Octane is essentially a measure of how easily a fuel will combust when put under pressure. The higher the octane, the higher the pressure it takes to combust the fuel. This also means that it is harder to burn the fuel. High performance engines run extremely high compression ratios which require high octane fuel so that it does not detonate. They get more power because of the higher compression ratios, not because of the higher octane fuel.

Since our engines can be run on 87 octane without detonating, they should be run on 87 octane (as long as it is not crappy quality). Since 87 burns easier, it will provide more energy per unit volume. So you are actually getting less performance from running 89.
I'll look into this more. This has been a huge debate among some of my other car friends and I, so this is not the first time I hear this. I have personally tested my cars using diagnostic tools, including this new car, and i actually get more performance running the 89. It is negligible, but it is still there nonetheless. You are not being a douche at all, just stating your opinion. There are always gonna be things people disagree on, and this is one of those topics that people ALWAYS disagree on. I know what works for me, and this is it. If you wanna save some money, then that's cool too.
 

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Here are my thoughts...

On vehicles that are made to run at a certain octane level, I normally won't go higher because, as was mentioned, the gain is slim to none. However, I'll NEVER go lower than the recomended octane.

I've owned cars in the past that called out 91 octane or better gas and running on 89 or 87 produced some pretty nasty results (wife filled up the car not knowing any better). The huge drop in mileage, rough running and lack of power was suprising. The same car on the European equivelent to what we'd call 95 was amazing too. It sang like a champ. On the flip side, I've run my other cars requiring 87 octane on "higher grades" and noticed no real changes...
 

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Discussion Starter · #18 ·
Not trying to start anything or be a douche, but that statement is not true at all. But wait! All of the race teams use high octane fuel, so that means high octance fuel = high performance, right? Not exactly. Octane is essentially a measure of how easily a fuel will combust when put under pressure. The higher the octane, the higher the pressure it takes to combust the fuel. This also means that it is harder to burn the fuel. High performance engines run extremely high compression ratios which require high octane fuel so that it does not detonate. They get more power because of the higher compression ratios, not because of the higher octane fuel.

Since our engines can be run on 87 octane without detonating, they should be run on 87 octane (as long as it is not crappy quality). Since 87 burns easier, it will provide more energy per unit volume. So you are actually getting less performance from running 89.
you speak a lot truth, sir. i'm too used to my old turbo car though. lol. imma try switch up the gas for now and see if that changes anything the next couple fill ups.
 

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Mine always over estimates. When I fill up the tank the display says my range is around 730km, but I usually get between 620-650km per tank.

My question is whats the most fuel anyone has gotten in their tanks. I believe the GT model has a 60L tank, I have run the tank down to the point that the range is 0km, but the car only took 53L to fill. I'm assuming the 7L is the reserve.
 

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There are always gonna be things people disagree on, and this is one of those topics that people ALWAYS disagree on.
This is not something that is argued in the automotive world (at least not among people who know what they're talking about). Unless you are changing your timing or running higher compression, 87 will be better for our engines (and any other engine that can run it without detonation).
 
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