Gas Premium or regular?

[Tcoat]

Originally Posted by carma143

I once brought my Dad to the gas station on the way back from Costco and he was yelling about the idiosy of the BRZ needing premium gas. One tank of 85 octane won't kill the car, right fellas?

Dealer filled it with regular before I picked it up. When I asked why their response was "premium is only recommended not required"! I was not impressed but to be honest it really didn't seem to make any difference through the break in period. It will never see regular again though.

Oh and FYI to you guys in the States that complain about the price of premium gas. Around where I live it costs between $5.50 and $6.50 a gallon!!!!!!!

[keithgold]

Originally Posted by Miss_Red

I was under the impression it was 11.5 (via the manual) I haven't risked running on empty as if yet (I don't plan to either.)

Have yet to fill more than $35 on my Escher (93 octane. Flying J fuel, only stuff I trust locally. Chevron with Techron is unavailable here and the fuel I only used in Houston. Cheap fuel killed my intake once.) Granted the fuel us a little pricier than unleaded; but sure beats filling up an SUV anyday.

Actually total tank size is 13.2 gallon or 50liter. Which makes sense for a Japanese car to use the metric system.

[mweidner311]

Originally Posted by Tcoat

Dealer filled it with regular before I picked it up. When I asked why their response was "premium is only recommended not required"! I was not impressed but to be honest it really didn't seem to make any difference through the break in period. It will never see regular again though.

Oh and FYI to you guys in the States that complain about the price of premium gas. Around where I live it costs between $5.50 and $6.50 a gallon!!!!!!!

You sir.... should move

[mweidner311]

Originally Posted by campy

I bet they don't have arguments about buying 93 octane over at Porsche and Ferrari boards

I thanked your post but you know what.... I bet they actually do just because there's always at least one asshat that thinks they know better then the design engineers or are literally just looking to save a few pennies on fuel.

It blows my mind how people would even consider putting regular in when on average premium costs what $3.00 - $3.50 more total on a full tank and that's here in Georgia where premium is .30 to .35 more a gallon. Back in Indiana it was in .10 cent increments so like $2.00 - $2.50 a tank

So.... save $3.00 and possibly take a risk on your $25k investment..... some people thought processes

You actually get better mileage with premium which would help offset the cost but you know I'm sure there will be arguments on that as well..

Have a good Labor Day weekend everyone!

[Kuros]

Anyone that thinks these motors with a 12.5:1 compression ratio can run right on anything less than 91 is sorely mistaken.

They already pull out timing on 91.
They really need 93

[Tcoat]

Originally Posted by mweidner311

You sir.... should move

Mostly tax. Don't think our Canadian health care is really "free" do ya?
Actually my area is CHEAPER then some.

[zooki]

Originally Posted by Kuros

Anyone that thinks these motors with a 12.5:1 compression ratio can run right on anything less than 91 is sorely mistaken.

They already pull out timing on 91.
They really need 93

And yet Mazda runs 1/2 a point higher compression in their Skyactiv motors on 87 octane. People are running boost on 93 octane. I think direct injection and variable valve timing lets you get away with a lot more in regards to cylinder pressures vs. octane ratings. Of course, tuning one of these motors for 87 octane would lose a little power, but I think it could be done easily. I wouldn't, but I don't see any technical difficulties in doing so.

[Ubersuber]

The fuel pump is not lubricated (gas is not a lubricant, diesel is).

Fuel cools the fuel pump. How important this is depends on the fuel pressure system fitted. Formerly, fuel pressure regulators returned excess pressure to the fuel tank, heating up the tank. I'm pretty sure all DI systems do not do this but circulate any excess pressure in a loop within the engine compartment.

Fuel pump cooling isn't an issue with the systems that circulate fuel within the engine compartment as opposed to those that return excess (and very hot) fuel to the tank. Older designs would kill their in tank fuel pumps if you persisted in running the tank down low. Later designs could care less.

The exact amount of fuel remaining when the fuel pump can no longer pick up enough fuel to deliver required line pressure varies from design to design. Certainly there is no fuel pump in any car that can completely empty the tank but it is feasible to get down to half a litre or so remaining which is a lot less than remains when that low fuel warning light illuminates.

On cars with a range to empty display you can always drive for quite some distance with the range to empty reading zero.

[Mikem53]

Originally Posted by Ubersuber

The fuel pump is not lubricated (gas is not a lubricant, diesel is).

.

Blah blah blah.. More erroneous BS from the master himself.
The gasoline does indeed lubricate and cool the fuel pump internals.
Gasoline is refined oil.. All one has to do is feel a drop of gasoline between your fingers to know its slippery oil that also lubricates..
But you go right on convincing yourself otherwise... I doubt anyone else
Finds any truth or value in your imaginary musings..

[Kuros]

Originally Posted by zooki

And yet Mazda runs 1/2 a point higher compression in their Skyactiv motors on 87 octane. People are running boost on 93 octane. I think direct injection and variable valve timing lets you get away with a lot more in regards to cylinder pressures vs. octane ratings. Of course, tuning one of these motors for 87 octane would lose a little power, but I think it could be done easily. I wouldn't, but I don't see any technical difficulties in doing so.

The skyactive motors run MUCH less timimg. MUCH less.

[zooki]

Originally Posted by Kuros

The skyactive motors run MUCH less timimg. MUCH less.

Generally speaking, the less total ignition timing you have to run the more efficient the combustion chamber design is, and the more power you'll make. If you could come up with a way to ignite all the fuel/air mixture at once(microwaves?), you could set the timing at TDC. We'll, maybe a degree or two before TDC to keep the connecting rods loaded against the crankshaft. I seem to remember Pro Stock motors from 10 years ago were only running around 10-12 degrees BTDC, due to the combustion chamber being so well designed.

[FlamingRectumSyndrome]

Originally Posted by rikdrt1

i hate our stupid state of CA. stupid Environmentalists and the Left movement have ruined our gas too. only 5 in the entire state have no Ethanol - im sure its down to 0 by now.... sucks - i remember buying 95octane or 100 in some places in the early days..

Hmmm... do you remember what the air was like in Los Angeles in the 1960s, before those pesky, leftist environmentalists pushed through some basic air quality standards? I do. For much of the summer, you couldn't breathe without coughing because the air was so toxic. I remember living in San Bernardino for a month before realizing there were hills only 300 yards away, the air was so thick with smog.

Then those awful lefties created CARB, the California Air Resources Board. It established restrictive, unreasonable, and unreachable goals regarding tailpipe emissions. There were two, distinctly different, responses to this:

1) Detroit bitched and moaned about unreasonable demands put in place by politicians who didn't understand the realities of how engines worked. The best they could do was to reduce compression ratios, building 350 cubic inch V8 engines that made something like 120 horsepower. They tacked on all kinds of half-assed contraptions like air injectors that would enable unburned fuel to finish burning in the exhaust manifold. They declared the Death of the Muscle Car and blamed it on California.

2) The Japanese sunk a small fortune into R&D to understand what was going on in the combustion chamber. If Detroit was building engines based in 1930s technology (two valves, push rods, combustion chamber architecture based on what was easy to manufacture), they decided to see if things couldn't be better. If engine performance was based on better breathing, why not adopt 4 valve technology that showed up in WWII vintage fighter planes and PT boats? They discovered that proper combustion chamber design gave massive dividends-- not only did it create less pollutants, it GAVE MORE HORSEPOWER. So engines could be smaller, cleaner, more fuel efficient, and more badass. Detroit struggled to make 50 horsepower per cubic inch. Japan made 100 horsepower per cubic inch the norm. I'm struggling to see the downside...

The end result, obviously was that people bought literal shiploads of Japanese cars while Detroit cranked out the same old $#!+ at faster and faster rates, creating huge problems with quality and reliability. They came -this- close to shooting themselves dead before realizing that they needed to step up to late 20th century technology and stop doing the same stupid things and hoping that their customers wouldn't notice. Goodbye points ignition and carburetors and a careless approach to weight management, hello fuel efficiency and effective engine design and actual engineering. The result can be seen in your driveway.

So stop looking to Rush Limbaugh for your answers, and embrace actual facts and engineering and physics. Those ignorant lefties gave you a car that's better than, say, a '63 Ford Falcon.

[zooki]

Actually 4 valve per cylinder (SOHC & DOHC) engines have been around as long as pushrod motors have. Several European makers had DOHC 4 valve motors as far back as the early 1920's, not to mention Duesenberg & Offenhauser both used this configuration in their cars before WW II. Many of the European companies used this configuration in their cars throughout the 50's & 60's. I will say the Japanese are good at refining existing technology. Insert something about "standing on the shoulders of giants" here.

[Ubersuber]

Originally Posted by Mikem53

Blah blah blah.. More erroneous BS from the master himself.
The gasoline does indeed lubricate and cool the fuel pump internals.
Gasoline is refined oil.. All one has to do is feel a drop of gasoline between your fingers to know its slippery oil that also lubricates..
But you go right on convincing yourself otherwise... I doubt anyone else
Finds any truth or value in your imaginary musings..

That would of course be why two stroke engines don't need oil in their fuel.

I have a vision of Castrol engineers rubbing gasoline between their fingers and nodding sagely among themselves: "you know, this stuff would make a great lubricant, wonder why nobody else thinks so".

Don't give up your day job in hopes of getting a job as a lubricant engineer, well, automotive lubricants anyway. I can think of one line of lubricant testing where your expertise might come in handy.

That rock over there is calling out your name: "come home...come home".