95 vs 98 Fuels

[mex351]

Why buy 91 when you can use 98 and your car will run better cooler and be more fuel efficient? Hell I use 98 for the mower and whipper snipper too and TBH the cost of it pales in significance against the cost Jim Beam cans ever since the Alcky Pops tax scandal...Grrrrrrrrrrrrrrrrrrrrr

So yes I use 98 even in my standard XF Ghia,our EF,our FG XR6 sedan and my ute (with a additive) and don't care about the price.

[Itsme]

Originally Posted by xisled

No I don't drive a late model xr6. I wouldn't bother with a 6 at all. But that's my opinion. My GT always gets 98. It been a few years since I owned a car that could run on 91.

Maybe it is because my daily is a V8, that the difference is minimal and I wouldn't notice it. but end of the day IMO unless your car is tuned for anything more than 91 using 95 or 98 will not make a a big difference.

Why make a comment about an XR6 if you cannot be bothered about one....
FG XR6 is recommended to use premium fuels and does make a difference

[Polyal]

Originally Posted by Coyote mk3

I'm sure a better average fuel economy is not psychological.

And I am sure you are driving exactly the same every time you change octane..same route, same temps etc etc...

The % difference is very little.

[superfly]

Originally Posted by bmorris

Hi all.

Just a comment for those out there who are using 98 oct fuel in their cars. I have a 06 BF XR6 four speed and have always used 98 fuels for as long as I have had the car. Recently I've switched to using 95 and have found my fuel economy has actually improved (I was expecting the opposite). I have noticed that the power seems to have decreased but only slightly and hardly noticable (but I expected as much).

Anyway I was surprised at the result and it could be food for thought for those like me finding it hard to justify the extra cost of 98 fuel.

Maybe someone who knows more about the science could explain why I'm getting these results.

When you switched from 98 to 95, was it from the same brand of fuel? e.g Vortex 98 to Vortex 95?

Some years ago I did back to back testing on a dyno with my old WRX. I tested BP Ultimate, Shell Optimax (as it was known as then) and Caltex Vortex 98. We ran an external fuel tank and pump. This test was more to prove the differences in the fuel and what power could be made on each fuel. At the end of the day, BP Ultimate and Vortex 98 were very similar but the Shell ran the car a lot richer.

I also did a lot of road testing of the different fuels over an extended period of time in variety of na models of cars.

Using BP Ultimate or Vortex 98 over any 91 ron fuel always yielded more k's out of a tank. In some cases, more power was noticed as well. In turbo charged cars they needed premium anyways so the difference between 95 & 98 was noticeable. But obviously tuning on 98 gave more power. I also got other people to test for me and some got hooked on the BP Ultimate as it now gave them more power and better economy which outweighed the extra cost.

Since getting my XR50, I've used BP Ultimate, Vortex 98 and 95 and some 91 RON fuels. The 91 RON fuel definitely gave the worst economy and felt more sluggish. Between the 98 and 95 there was not much difference so these days I only use Vortex 95. In my wife's WRX I only use BP Ultimate as that is the best fuel for the WRX IMO.

[2011G6E]

The massive price difference puts most people off.

That and the fact that there's no real benefit to the vast majority of drivers. Yes, we tried it in our G6E on a long trip down to Brisbane, and the fuel economy might have been a bit better, but the staggering difference in fill up price means that small benefit is eaten up by the extra fill up cost.

It's also worthwhile remembering that there is a subconscious factor in any fuel economy enhancer...from magnets on the fuel line, to nitrogen in the tyres, to HiClones, to any other expensive thing that is claimed to increase economy.
When you are spending the big money, and looking for increased economy, you will unknowingly start driving more "efficiently" and watching your fuel gauge more intently. You might not know you're doing it, but once you are just doing what the motoring organisations are telling you to do...rolling to a stop, accelerating more gently, keeping your car in a better state of tune, etc.

You won't realise you're doing it, but you will be.

[au3 220]

I use a tank a week and i get 500 clicks each and every time on 98. I time it so i fill up during the cheapest period of the week this way i pay the same as those that pay the nearly 20c extra that 91 (and 95 and 98) goes up freakin overnight. Now here's another angle. Current AU3 XR8 and previous 2000 pulsar sss drank 98 and have given me ten years combined of no fuel filter change, no injectors cleaned..... not once. The proof's in the pudding that 98 (along with regular oil,filter change and maf clean) keeps my girl clean and running like brand new. Worth every cent i say.

[Drizz06]

Originally Posted by mex351

Why buy 91 when you can use 98 and your car will run better cooler and be more fuel efficient? Hell I use 98 for the mower and whipper snipper too and TBH the cost of it pales in significance against the cost Jim Beam cans ever since the Alcky Pops tax scandal...Grrrrrrrrrrrrrrrrrrrrr

So yes I use 98 even in my standard XF Ghia,our EF,our FG XR6 sedan and my ute (with a additive) and don't care about the price.

Haha I run my ride on and lawn gear on 98 too!
I fill the Jerry cans while I fill the car so it's just easier to use same pump.
Seems to last longer in storage to.

[superfly]

Originally Posted by 2011G6E

The massive price difference puts most people off.

That and the fact that there's no real benefit to the vast majority of drivers. Yes, we tried it in our G6E on a long trip down to Brisbane, and the fuel economy might have been a bit better, but the staggering difference in fill up price means that small benefit is eaten up by the extra fill up cost.

Staggering difference??? Vortex 95 is 10 cents dearer a litre. So over 60L that's an extra $6.

And you won't notice the fuel economy improvements on long distance trips. Fuel economy is already at its best then.

Originally Posted by 2011G6E

It's also worthwhile remembering that there is a subconscious factor in any fuel economy enhancer...from magnets on the fuel line, to nitrogen in the tyres, to HiClones, to any other expensive thing that is claimed to increase economy.
When you are spending the big money, and looking for increased economy, you will unknowingly start driving more "efficiently" and watching your fuel gauge more intently. You might not know you're doing it, but once you are just doing what the motoring organisations are telling you to do...rolling to a stop, accelerating more gently, keeping your car in a better state of tune, etc.

You won't realise you're doing it, but you will be.

Don't agree with this one bit. I don't drive more fuel economy aware when I'm checking my fuel economy. I'm still the first one to be away at the lights when I can. And if I have 91 RON in my XR50, it feels slower when taking off.

In one of my previous non turbo cars, I filled it up with BP Ultimate. I then let my ex drive it around. She claimed that I had modified the car as it was now faster. An older bloke at work had the same car. I got him to try it. At first he wasn't willing so I offered to refund him the extra money he'd spend on the 98 over 91 if he didn't notice a difference. Suffice to say, he noticed both more power and fuel economy.

But this may not be applicable in all cars as I mentioned in my previous post.

At the end of the day though, if using a premium fuel doesn't make any difference for you, then just don't use it.

[TZENU]

I am getting longer mowing time out of BP98 then regular 91

[xisled]

Originally Posted by trublu

Why make a comment about an XR6 if you cannot be bothered about one....
FG XR6 is recommended to use premium fuels and does make a difference

Because it is a forum and I am giving my opinion, nothing more nothing less.

End of the day I think it is a waste of money to put anything above 91, into a car that can use 91.

[mex351]

Originally Posted by TZENU

I am getting longer mowing time out of BP98 then regular 91

Wonder if I drink the stuff If I would last longer in bed too...

[xisled]

Originally Posted by mex351

Wonder if I drink the stuff If I would last longer in bed too...

LOL I think you need AMI for that.

[mex351]

Originally Posted by 2011G6E

The massive price difference puts most people off.

When you are spending the big money, and looking for increased economy, you will unknowingly start driving more "efficiently" and watching your fuel gauge more intently. You might not know you're doing it, but once you are just doing what the motoring organisations are telling you to do...rolling to a stop, accelerating more gently, keeping your car in a better state of tune, etc.

You won't realise you're doing it, but you will be.

Who would have though a extra $6-7 a tank is such a massive amount of money...LOL Really the amount can be made back by not buying a coke and Mars bar at the servo when you pay for your fuel...LOL

[Fiesta_Man69]

Originally Posted by Polyal

And I am sure you are driving exactly the same every time you change octane..same route, same temps etc etc...

The % difference is very little.

Wrong.

Over several thousand kms conditions even out.

Consistent better milage is proof.

I've owned more than a dozen cars, and my experience is that 98 works out cheaper per km than 91 with the added bonus of extra hp to boot.

Works out to be hundreds of dollars ahead over the years buying the better fuel. Win/win.

[xisled]

What you really need to do, is work out how many more ks you’re getting out of the tank on average, using 98 or 95 instead of 91, then work out the cost of each, and decided for yourself if using a higher octane fuel is better or not. Each car is different, everyone will get a different result, it is like the E10 argument. Some say their cars love it while others say it hates it.

End of the day it is your money going in to the tank and your car will not be hurt by using a higher octane fuel.

[PHATXR8]

In the wife's Turbo Territory (stock engine except for K&N filter) the difference between 91 and 95 octance is 11% better fuel economy (have tried it several times on long distance freeway trips). Performance when overtaking is also improved dramatically.

Then the difference between 95 and 98 seems to be a further improvement of about 5% in economy. Negligible performace improvement noticed.

So overall the extra cost is more than justified.

In my F6E, the 98 octane gives much better economy over 95 (somewhere about 7% to 10%) and is noticeably sharper accerelation. Car is stock except for a K&N Filter.

[jmack]

not saying your figures arent true but all these claims 10% and more better fuel economy seem hard to beleive when car companies spend a fortune on lightning cars better aero,better tuning,more gear ratios when all they had to do was specify 98 fuel and save their money on r&d and claim the new modl is 10%more eff than the last,i think a lot of its like a placebo pill,but i do agree some engines like the better fuel,mine dosnt like shell98 but runs ok on bp98 but its not a standard motor or tune

[FPV+fteT3]

For the record I use 98 the cars are tuned for it. All the economy longer mileage stuff aside, compare an engine pulled down using 98 to one using 91 you would never put 91 in anything again. Ask any mechanic, any type of car, any type of motor, for an internal engine component comparison between fuels. I guess if you dont intend on keeping the car for an extended period even the old 2 stroke out of the boat tank could be used its probably still ok.

[Itsme]

Originally Posted by FPV+fteT3

For the record I use 98 the cars are tuned for it. All the economy longer mileage stuff aside, compare an engine pulled down using 98 to one using 91 you would never put 91 in anything again. Ask any mechanic, any type of car, any type of motor, for an internal engine component comparison between fuels. I guess if you dont intend on keeping the car for an extended period even the old 2 stroke out of the boat tank could be used its probably still ok.

I've rebuilt many engines in my time and the condition of the engine comes down to how well/often was that engine serviced with what type of oils used before worrying about what type of octane fuel used.
Then it comes down to how rich or lean the fuel is when running.

[2011G6E]

Originally Posted by trublu

I've rebuilt many engines in my time and the condition of the engine comes down to how well/often was that engine serviced with what type of oils used before worrying about what type of octane fuel used.
Then it comes down to how rich or lean the fuel is when running.

Yep...there's a lot of things you can do to your car to increase it's fuel efficiency or how well it runs...and leaving it as is and paying 10 cents or more per liter for fuel extra should be way down the list...

[BA-XT]

The BA's do apparently respond well to higher octane fuels. Can't find the link at the moment, but it was discussed in detail when the then new barra engine was released.

I only use 95 or 98 with a splash of Flashlube Injector cleaner. I don't do it so much for the economy, more to keep the valves clean.

There's a demonstration on you tube. Type in "shell v-power" and you can see how well the fuel cleans compared to 91 octane.

[superfly]

Originally Posted by 2011G6E

Yep...there's a lot of things you can do to your car to increase it's fuel efficiency or how well it runs...and leaving it as is and paying 10 cents or more per liter for fuel extra should be way down the list...

Like what? What else can I use for $6 a tank that gives me better economy?

Just cause it doesn't "work" for you, doesn't mean it's not true.

[XR6T0Y]

Filled up 3 days ago now, 75$ for 618k's. Better than the 80$ and 514 k's when I was using 95. There is NO WAY that someone is going to convince me that 98 isn't better unless tuned to it

[xtremerus]

A better than 20% improvement in economy from using 98 instead of 95, I find hard to believe.
That is just assuming the 98 was the same price/L as 95 that you put in.
Litres used is a more accurate measure of economy, that dollars.

[Drizz06]

Considering most spent $1000's to get more power from there engines! If you can notice a boost from using 98 then I reckon it's a cheap power booster at $6 a fill.

[flappist]

Big picture:

You are driving a $40k-80k vehicle (or even a $5k AU or whatever) that costs $20/w rego and $10-40/wk insurance.

If you do 25,000km/year (which most of you do not even come close to) @ 15l/100k (which almost all get better than) you are using 3750l of fuel.
Even if you use exactly the same amount and the difference is 10c/l (which it is always less than) you are talking $375/yr or about $7.50 per week.

Redo those calculations at your ACTUAL km/yr, l/100 and pump price difference and the number drops below the price of a cup of coffee.

So how about you buy one less "Half double decaf half caf grande latte frapichino with double foam and extra dollup" from that fabulous cafe between your hairdresser and manicurist and be nice to your car by filling with the best fuel available.

[XR6T0Y]

Originally Posted by xtremerus

A better than 20% improvement in economy from using 98 instead of 95, I find hard to believe.
That is just assuming the 98 was the same price/L as 95 that you put in.
Litres used is a more accurate measure of economy, that dollars.

You may find it hard to believe, but I see it on my dash everytime I fill up, so...



This was taken about 3-4 weeks ago, and is slowly going up

[flappist]

Originally Posted by XR6T0Y

You may find it hard to believe, but I see it on my dash everytime I fill up, so...

image

This was taken about 3-4 weeks ago, and is slowly going up

I used to play games with my AU back in 2001 where I wold just about run it out of fuel, put in $5, run it down, put in $5 a couple of time to see just how high I could get it to read after a fill up.

My goal was 999 but the best I got was about 920 (7.3l/100) which is not bad for crappy old VCT auto ghia .

Do not trust the DTE gauge, it tends to tell fibs......

[xisled]

Originally Posted by XR6T0Y

You may find it hard to believe, but I see it on my dash everytime I fill up, so...

image

This was taken about 3-4 weeks ago, and is slowly going up

Both my falcons show strange amounts when I fill up. I put it down to the tacho working it out using the average speed and how many liters I fill up.

The best way to work out what is better for your car. Fill your tank twice with each type of fuel, drive the same way and take the same route around the same time and Zero the trip computer each time you fill up, Run the car to empty and see how many ks out of each tank you get.

[jpd80]

In the past I have found that 95 is the best balance with several FGs I have driven,
they all seemed to run much nicer r in around the traffic but only slightly better economy...

Probably because I-6 has been optimized on 95 not 98, hmm maybe that 12:1 set up off EcoLPi and 98......