Gas Grade???

[Daelen Nekuda]

Hey i was just wondering if gas grades make a difference in performance???

[Canadian Turbo]

Re: Gas Grade???

Yes higher octane means better performance.

[Khyron]

Re: Gas Grade???

Common misconception. Higher octane is not a "treat". An older civic or VW will not normally see any benefit, and may even see worse performance/fuel econ by using a higher grade. Unless you have an EMS, go by what your manual says, or whatever you need to stop knock.

The cleaning additives in the higher grades can be nice, but you're better off dumping a bottle of injector cleaner every oil change and stick to the regular.

Khyron

[Kor]

Re: Gas Grade???

He drives an '01 Golf, so his ECU will adapt timing if he sticks with a higher octane fuel. I think Blair was just giving a simple answer to a simple question.

[R_Ethug]

Re: Gas Grade???

120 helicopter octane all day everyday for me

[Kor]

Re: Gas Grade???

Besides performance

1. High-octane gas is 3% denser than regular which may increase fuel economy

2. In Canada all companies that offer premium gas add other additives to it that are supposed to keep engine parts cleane and reduce emissions.

[Aleks]

Re: Gas Grade???

Ahhh, good ol 94 oct. all the time.....nothing beats 90+ cents/litre.....I notice a difference in performance, and always have, maybe its all in my head......Moreso now though with the chip....

[R_Ethug]

Re: Gas Grade???

no its not in your head alex.. my APR was noticably faster with the 94 and 93mode.. according to apr 8HP and 10tq more..

[Khyron]

Re: Gas Grade???

Besides performance

1. High-octane gas is 3% denser than regular which may increase fuel economy

2. In Canada all companies that offer premium gas add other additives to it that are supposed to keep engine parts cleane and reduce emissions.

Marketing marketing marketing!

The 2.0 has knock sensors to retard timing, but it's not going to go much above the factory map just because you put in 94. And the whole point of higher octane is it takes more pressure before it will spontaneously combust, which has a penalty in that it doesn't burn as fast which actually makes the burn less efficient. Timing may change slightly but your compression isn't. Higher octane strictly speaking makes a worse burning fuel, BUT that minor con is overshadowed by the pro of being able to increase compression/boost. So you lose a 4 hp but gain 15 for instance.

Any auto manufacturer engineer will tell you to read the label in the back of the fuel flap and to use that - anything more is just burning money, UNLESS your engine is knocking.

Consider, if your car magically adapts to it, why is there a specific APR 91 and a 93 and a 100 program? Because the programing is THAT specific. You can't put 93 octane into the 91 program and expect to adapt to 93 program levels.

The additives can also do more harm than good - was it Shell or Esso that killed thousands of engines because of one of their additives? Use an injector cleaner every now and then.

Now, the 2.0 may very well have 91 on the sticker behind the fuel door, but since it's the base model I highly doubt it was tuned to use premium. Unless of course you slap on a supercharger.

Listen to the guys that build the cars, not the oil company marketing department.

Khyron

[Stonewall]

Re: Gas Grade???

I have to say Geoff you make a compelling arguement. I don't pretend to know much about gas engines but I do know a lot about physics and I can see where you are comming from.

[Kor]

Re: Gas Grade???

The increased density can increase economy and has nothing to do with timing. Gas companies due claim it does more than it actually might, however independant studies have shown there is a small positive effect.

Moreover, I am not saying that your car will magically adapt to any level of octane, however in Calgary a high octane fuel is only 91, which is not exactly race gas.

There was an incident of additives causing problems, however this doesnt mean all additives are bad - that is just being silly. If there is an incendent in which someone eats a bad bagel, it doesn't mean bagels are bad for you.

Honestly most people who cry out against premium gas seem to protest too much, with conspiracy theories and accusations that there is some effort to pull the wool over people's eyes and steal their hard earned pennies per tank.

[NeonGTI]

Re: Gas Grade???

Calgary 91 is equivalent to sea level 93. As altitude increases the propensity for pre-ignition decreases (the air is less dense, thus less prone to ignite). Good ole Mohawk 94 is on par with sea level 97-ish.

I have found, from purely a qualitative point of view, that with any of the dozen-ish vehicles I have owned that idle and power delivery is smoother with a higher octane of fuel. I don't claim there is ANY improvment in performance at all, but the feel of the car is better.

With my GTI 1.8t I have to trim back the SPS3 if I have premium 91 in the tank, but with Mohawk 94 I can run 'full out retarded' mode. Curiously though with my 00 Passat 1.8t it ran strong as an ox with regular old 87 in it. It felt stronger actually. I filled the tank with 87 a couple days before I dropped it off at the dealership after I sold it.

Oh, and if you are driving on the highway with little or no full throttle runs you can run regular. If you aren't at full bag, and aren't lugging the engine octane really isn't a factor.

As gas prices increase premium gas is a better and better deal. When gas was $.50 premium was $.60, now that gas is $.80 premium is $.90. No inflation!

[LaDubDude]

Re: Gas Grade???

Marketing marketing marketing!

The additives can also do more harm than good - was it Shell or Esso that killed thousands of engines because of one of their additives? Use an injector cleaner every now and then.

Khyron

It was Shell . . . I know a guy who runs a station here in Halifax. He was pretty stressed from all the complaints and it cut into his biz (the company waffled for a couple of months before offering coupons and considering repairs). I was living in ON at the time and can remember lots of stories in the paper and on TV about wrecked fuel pumps - mostly in Chrysler products I think.

When I was living in Ontario, I made lots of trips between T.O. and Halifax. I was driving a 1986 Golf at the time . . . no computer to control timing, ignition, etc . . . (in fact, I'm pretty sure that the only computer in the car was the digital dash clock).

I first bought the car while in school and put nothing but 87 octane in it for a few months. It idled horribly and was a rough starter even after I cleaned and fixed everything that needed doin' (not overly complicated with CIS fuel delivery). Fuel system was OK, compression was OK, plugs and wires were new, cap was new, etc, etc. . . One day, not wanting to wait in line at the pumps, I just filled the beast up with supreme at Pioneer (Sunoco gas) and, like magic, the thing started running and starting like I thought it should. The real kicker is that my fuel economy was increased to the extent that the extra couple of bucks for supreme was a steal. I got roughly 100 additonal KMs per tank highway running into prevailing winds heading east. I was amazed.

I've read many articles that essentially say putting supreme in a car like that is a waste of money but, unless something just happened to click at the exact same time as i switched to supreme - kind of a strange coincidence - the pricier fuel made my car smoother and cheaper to run. I tried going back to regular and, whether highway or city driving, my mileage was better on supreme.

[Flanders]

Re: Gas Grade???

Besides performance

1. High-octane gas is 3% denser than regular which may increase fuel economy

2. In Canada all companies that offer premium gas add other additives to it that are supposed to keep engine parts cleane and reduce emissions.

actually, higher octane fuel actually burns a bit dirtier than lower octane stuff (although it is more dense, and less prone to detonation). To compensate, manufacturers add cleaners (like petrocan adds tractol) which compensate for it.

All the cleansing additives in higher octane feul are there so it burns just as clean as the other grades...it's a marketing scam that makes you think that your car needs them to run uber-clean!

Good read on gasoline:
http://members.shaw.ca/VintageVehicles/GasandOctane.doc

[Khyron]

Re: Gas Grade???

The increased density can increase economy and has nothing to do with timing. Gas companies due claim it does more than it actually might, however independant studies have shown there is a small positive effect.

Ok so to sum up, you're claiming that an X amount charge of higher octane fuel burns with more energy than an X amount charge of lower octane? So it uses less? Because that's what you're saying above.

Since the X charge is denser, it will just make you run richer than before when not at WOT. Most cars already run rich so you're just making it worse.

Honestly most people who cry out against premium gas seem to protest too much, with conspiracy theories and accusations that there is some effort to pull the wool over people's eyes and steal their hard earned pennies per tank.

Watching sheep get convinced by advertisers that they need to put premium in their old minivans or base civics is as agravating as listening to greasy computer salesmen telling grandma she needs to spend get a 9800 Pro so she can surf the net faster. Are you going to buy a Tornado for your intake? Or a fuel magnet?

If you had problems, and higher octane fixed it, a tune-up would have probably done the same thing (and will extend the life of your car more than masking the problem with better gas). I'm not saying it's complete snake-oil, but don't just blindly buy it because you "think it will be better".

Another quote:

Even if the engine does adjust for the higher octane, the maximum advantage is generally around one per cent increase in engine power (or reduction in fuel consumption) per octane number. Unless the price of the higher octane fuel is less in cents per litre than the difference between the fuels in octane numbers, it is probably not economically worth your while using the higher octane.

http://www.vmclinks.com/x/modules/tu...ial.php?tid=10
http://www.handymanusa.com/articles/octane.html
http://www.epinions.com/auto-review-...39237DBB-prod6
http://www.motorcycle.com/mo/mcnuts/rt-fuel1.html
http://www.dynobike.com/news0404.htm

Seriously, show me a link that shows higher octane benefits without remapping for an NA car.

Khyron