Husky 94 vs. Shell 91 Actual Test

[blktopbig28]

It started with a single question: "What fuel should I use for my modded high performance vehicle?" General consensus after browsing some of the threads was that Husky offers up best power and Shell is best for fuel economy. BUT... how much better is each at their respective strengths?

So... I decided at the start of this summer to conduct a test to see if there is any difference between Husky 94 and Shell 91 and attempt to quantify any differences.

How I did the test: Started beginning of June 08 to end of August 08. Alternated between Husky and Shell, usually 3 fills before switching to the other brand. Ran until fuel light comes on and filled up to the top. Drove in a manner to maximize fuel economy. I use one test tank before switching over brands to run it hard and logged to see if computer pulls any timing. The test tank is not part of fuel economy numbers. The mix was 90% city and 10% highway (I considered Deerfoot as city driving).

Vehicle: 2004 WRX Hybrid (STI motor). Built engine with all the usual bells and whistles. Full stand alone computer with a fairly conservative map tuned for 93 octane at sea level. Approx 350 whp.

Fuel Economy Results:

1 gallon approx 3.78L
1 mile approx 1.6 KM

Shell - 3,786 kms on 433.0 L = 20.66 mpg
Husky - 4,279 kms on 504.4 L = 20.05 mpg

On my car, Shell has about a 3% advantage based purely on fuel economy. Of course this is not the most scientific of tests given that conditions were never the same, but over the length of the test I assume that law of averages evens out some of the anomalies.

Timing Results: Set boost level at 20 psi.

Shell - pulled anywhere from 2-4 degrees of timing in high torque range (4000 to 5000 rpm) from 8 to 14 psi range. It was fine after that.
Husky - computer did not retard timing at all.

Husky is definitely the better choice for those that want a better degree of protection.

Conclusion: ON MY CAR, I would use Husky 94 and gladly give up the 3% fuel economy difference for the added protection (which equals power). Of course, every car is difference so please take my results with a grain of salt.

Disclaimer: I am NOT an expert whatsoever. Just an average guy with a question that I wanted answered. I'm sure that there are many smarter guys out there that might question the results and ask for "technical" backup. But I'm not really in a position to explain or defend it, just wanted to post my findings.

Hopefully this might give some insight to those that had the same question I had.

Tom

[ekguy]

so let's say you have a car that says specifically to use premium fuel only would I be better with the higher octane content of Huskie's fuel?

[Revhard]

On an n/a car, it shouldnot matter at all. The elevation reduces the risk of pulling timing anyway. A car requiring premium from the factory could run on 89 here in theory.
Running 91 would be a large safety margin. That said, I also found there to be no difference in the economy between the 2, so price is the only real deciding factor on an n/a or factory boost car.
Good job on the test.

[ekguy]

thanks. Gas is going down pretty quickly so maybe 94 octane gas might be in the near future for me.

[Casa]

Originally posted by ekguy
thanks. Gas is going down pretty quickly so maybe 94 octane gas might be in the near future for me.

94 Octane is a waste of money for a car that requires premium.

[Sorath]

on all cars ive owned before i find that i knock less on shell 91 than on husky 94.

but for some odd reason i think my STI likes husky 94 better

[ekguy]

I use Petro premium though. Much closer to my house than any shell station.

[Sorath]

petrol is the worst gas out of all to put in a performance vehicle. but i guess if its a stock car it doesnt matter

[Redlyne_mr2]

Originally posted by Sorath
petrol is the worst gas out of all to put in a performance vehicle. but i guess if its a stock car it doesnt matter

[FLARE]

My silvia craves husky 94 over shell 91. My level of knock increased by roughly 5% with shell.

However, my tune was done on husky 94 and at 17 psi. Tomorrow I have to gas up, and will try on 20 psi and update later this week.

[ekguy]

Originally posted by Sorath
petrol is the worst gas out of all to put in a performance vehicle. but i guess if its a stock car it doesnt matter

with the venom performance module turned off I'm sure it doesn't matter but with it on it's remapping the fuel map and shit like that I think. Maybe i should just stop being lazy and drive to Shell instead of going down the road to petro.

hahaha but you turbo guys must really have to watch what your cars are drinking.

[badatusrnames]

I've heard of fuels with oxidizers (such as ethanol) in them corroding injectors on some cars and leading to failure.

Can anyone comment?

Husky 94 is 10% ethanol IIRC.

[94boosted]

Originally posted by badatusrnames
I've heard of fuels with oxidizers (such as ethanol) in them corroding injectors on some cars and leading to failure.

Can anyone comment?

Husky 94 is 10% ethanol IIRC.

Good read about ethanol:

http://www.ncga.com/Ethanol/main/your_car.htm

[badatusrnames]

Originally posted by 94boosted


Good read about ethanol:

http://www.ncga.com/Ethanol/main/your_car.htm

Haha yeah, like that isn't biased. We all know that US corn growers need a few more billion dollars of subsidies.

Regardless, that link speaks about ethanol (not) leaving a residue that will plug fuel lines and injectors. I was asking more about corrosion due to the oxidizer (ethanol) in the fuel. Like what is mentioned here:

http://www.jimwolftechnology.com/wolfpdf/Z32EARLYSTYLEINJFAILURE.pdf

[Mibz]

Whoever said 94 is a waste for premium only cars is bang on. If you're not tuned to 94 or have a PCM that will adjust to it then it's a waste of money and a tiny bit of power.

[Xtrema]

Tried it once on my VQ35DE. Does nothing but give me 10% less kms.

Never again.

Although the owner manual did say ethanol is fine as long as it doesn't exceed 15%.

[ShermanEF9]

Originally posted by Xtrema
Tried it once on my VQ35DE. Does nothing but give me 10% less kms.

Never again.

Although the owner manual did say ethanol is fine as long as it doesn't exceed 15%.

My car HATES ethanol... doesn't matter how much.
it bogged out, it surged, it once wouldn't start... filled up with shell and all was good

[GQBalla]

all gas has ethanol now...10% iirc that has been set into place by the government?

i think?

[Fuji]

The whole topic of fuel, esp for modded subies has been slammed to death over the last 7 years. If you search the canadian forums on Nasioc.com you'll find more info

[Eleanor]

I'm pretty sure GQ is right. AFAIK all gas in Canada has ethanol in it :dunno:

FLARE, if you're tuned on 94, of course you're going to knock on 91 :banghead:

Sherman, are you tuned on 94?

[Kloubek]

Almost completely off topic - did you guys see the Mythbusters episode where they ran a diesel engine off nothing buy used vegetable oil? Worked crazy well, with just a 10% reduction in "fuel" economy.

[2002civic]

good to know..

[rage2]

Excellent writeup. Pretty much the same results I got when I did the same test with 4 different brands when 94 was introduced here.

BTW - for those that "hate" ethanol, every gas has ethanol in it these days. In fact, in the US, Shell has just as much in it as 94 Mohawk/Husky.

[FLARE]

Originally posted by Eleanor
I'm pretty sure GQ is right. AFAIK all gas in Canada has ethanol in it :dunno:

FLARE, if you're tuned on 94, of course you're going to knock on 91 :banghead:

Sherman, are you tuned on 94?


OHHH ya, this is why I rarely post on beyond nowadays, because people bash you for any reason! YAY...

Would it have been better if I didn't try the test and just shut the fuck up ELEANOR?

I figured someone would like to read the little tid bit of info; but thanks you knocked me back into using beyond as a newspaper.

[Eleanor]

It probably would've been better on your engine if you didn't run the test.

"Hey guys, my car is tuned on 94, but I'm going to run lower octane, just to see what happens!"

"Guess what guys, it ran like shit!"

:nut:

[Mibz]

Originally posted by FLARE



OHHH ya, this is why I rarely post on beyond nowadays, because people bash you for any reason! YAY...

Would it have been better if I didn't try the test and just shut the fuck up ELEANOR?

I figured someone would like to read the little tid bit of info; but thanks you knocked me back into using beyond as a newspaper. What are you so butthurt about? He's right.

Run the octane that your car is tuned for, it's as easy as that.
If you're tuned for 91 and run 94 then you're making a mistake.
If you're tuned for 94 and run 91, you're making a mistake.
If you're tuned for 89 and run 94, you're making a mistake.

[FLARE]

Originally posted by Eleanor
It probably would've been better on your engine if you didn't run the test.

"Hey guys, my car is tuned on 94, but I'm going to run lower octane, just to see what happens!"

"Guess what guys, it ran like shit!"

:nut:

I street tuned it with the help of a fellow beyonder, and wanted to see for myself if going down to 91 was going to do anything. What's the harm?

My engine didn't "run like shit" as you've posted; The variation of 5% knock brought me up from 5ish to 10ish, SOOOOO conclusion = Did go up in knock, but NOT ENOUGH to harm my engine.

I definitely took that as a Positive Outcome.

Thanks for bashing though, I love the frienship.

Edit: I had the power fc commander plugged in while I tried this out, so if I had seen a lot of variation in knock, I would've modified it so that it didn't ruin my engine.
I thought I should put something in this thread about it, because thats the topic of the thread. Am I so wrong?

[Supa Dexta]

5 counts of knock to 10? Hell I try to stay under 1... In my ems showing "10".. would be 10 Degrees of Knock Retard, or 35 "counts" of knock though.

[rage2]

Originally posted by FLARE
OHHH ya, this is why I rarely post on beyond nowadays, because people bash you for any reason! YAY...
So pointing something out is bashing now? :dunno:

[FLARE]

Originally posted by rage2

So pointing something out is bashing now? :dunno:

Ouch rage, I had a feeling you were going to support the fact that I was adding valid information and not just "pointing out" how dumb people were :cry:

I really hope my account doesn't get banned again for these posts.. if they are on the verge of causing that, please do pm me and tell me to shut the F up.

[FLARE]

Originally posted by Supa Dexta
5 counts of knock to 10? Hell I try to stay under 1... In my ems showing "10".. would be 10 Degrees of Knock Retard, or 35 "counts" of knock though.

The beyond member who helped me with the tuning process told me that anything under 20 (this is on the power fc commander) is fine. So going from a 5 to a 10 really didn't mean to much of a problem; hopefully this is good info haha

[Skyline_Addict]

interesting write up. i will try this out with the s2k.

but ya Flare, Eleanor was just pointing out a fact. it almost seems like you were just expecting someone to start bashing you and took the slightest degree of forwardness from Eleanor way too hard. rage isn't going to ban you just because he didn't "back you up".

just stop being so sensitive, it's an internet forum.

[rage2]

Originally posted by FLARE
Ouch rage, I had a feeling you were going to support the fact that I was adding valid information and not just "pointing out" how dumb people were :cry:
I'm glad you're adding info to the thread. I'm just kinda curious how u felt that comment was bashing you. It just pointed out the obvious... tune for 94, use 91, you get knock. He was adding info to the thread as well.

You're not gonna get banned lol, if anything I was gonna point you to the door for crying over nothing :rofl:.

[hypnotoad]

Originally posted by FLARE
[B] OHHH ya, this is why I rarely post on beyond nowadays, because people bash you for any reason! YAY...
Would it have been better if I didn't try the test and just shut the fuck up ELEANOR?


Don't worry about that, about 60% of beyond members are just losers sitting around waiting to bash people, just ignore them and keep posting as much as you want.

[QuasarCav]

Originally posted by Skyline_Addict
interesting write up. i will try this out with the s2k.

but ya Flare, Eleanor was just pointing out a fact. it almost seems like you were just expecting someone to start bashing you and took the slightest degree of forwardness from Eleanor way too hard. rage isn't going to ban you just because he didn't "back you up".

just stop being so sensitive, it's an internet forum.


What are you going to try out?

I usually get the same results that the OP discovered. The IAM is a good measure of the knock levels experienced on my Subaru. The full IAM value is 16 which will use full ignition advance where anything below 12 indicates that the engine has detected moderate knocking.

On the Accessport Stage 1 91 Octane map:

Shell 91 = IAM 14
Petro 91 = IAM 2!!!!!!!!
Husky 94 = IAM 16

[Sorath]

are u using the acn map or no?

[benyl]

Even when my STi was stock, it ran better on 94. I ran 94 because Husky was 5 blocks from my house.

Haven't tried the 335 on 94 yet as it out of the way for me to get it.

When I did this same experiment, I got even better mileage out of the 91 Shell.

94 got me about 350kms to a tank (50L). 91 got just over 400kms. I wasn't driving the same way. With 91, I would always back off when the knock light started flashing. Just couldn't drive the car as hard and is probably why I saw an even bigger difference in mileage.

[zipdoa]

So on my car, inside the gas flap, it says 87 min 91 rec... I always use regular, premium wouldn't make a difference would it?

How about after I get cams/intake mani installed w/ standalone fuel management, could I get it tuned to 94 and make a little more power?

[QuasarCav]

Originally posted by Sorath
are u using the acn map or no?


No. I was instructed to use it by the seller of the Accessport but after using Shell 91 on the 91 Octane map with the IAM at 16 I did not worry about it.

I have a hard time driving the car with the 91 Octane map because the 93 is just so much better, the car actually responds to throttle inputs below 2500RPM and it will produce power in the high range as well. Husky also gets along better with the economy mode. I managed to get 33MPG on a trip to Medicine hat and back.

[Sorath]

hmmm so are u running a 91 map or 93 map?

cause right now im running a cobb stage 2 LC map. and just wondering if u had any input.

I feel that my car boosts easier and smoother with the 94.

[QuasarCav]

I run the 93 map most of the time. 94 Octane is just as close to home and it's only 0.02c more. The 93 maps will lean out the AFR by around .5 and add a bit more timing. It definately feels more lively around town.

IIRC timing at full boost in 3rd was around 15.5 with the 91 and 17-18 with the 93 map.

[Sorath]

hmmm i should try that out tonight. i wonder if the 93 map might work better for my application, cause right now im getting terrible milage, and most of my commute is highway. i get about 300-320 to a tank

[benyl]

Originally posted by Sorath
i get about 300-320 to a tank

Boost leak?

[Sorath]

i dont think so.

on the accessport, i checked the narrowband they have there, and it only reads to 11.0 afr, and its showing that, so i know the afr is below 11 all the time, hence my gas milage i think...

[Carlton]

Originally posted by Sorath
i get about 300-320 to a tank

Ferrari gas mileage nice.

[QuasarCav]

You at 11 even when cruising?

I find the AFR trys to stay around 14.7 unless you are WOT. STi's do get shit for mileage 300-320 is not out of spec if you are driving hard.

If you are stage 2 do you have a cat back only? Any other mods can really screw with the off the shelf maps.

[benyl]

Get yourself a wideband.

[Sorath]

naw, its just 11 at wot, 14.7 for part throttle.
i think im gonna get a wide band.

ive got a on top of turboback exhaust, sri and perrin crank pulley

maybe im just used to the gas milage in the civic si LOL :(

[xrayvsn]

Sorath, I can pull some datalogs for you if you want to see if the ECU is knocking or not, or lend you my Tactrix cable if you already have a laptop.

Try the AP Stage 2 93 Octane map and Husky94. I am going to suspect you will show 1-2 degrees of pulled timing from knock at boost onset as the ECU is switching from closed loop to open loop fuelling based on my experience. The Cobb maps also tend to overboost, which doesn't help.

I saw det on 06/07 STi's running the 91 Octane map and using Shell 91. I also had a few tanks of Shell 91 result in 2 - 4 degrees of learned knock correction, and I am tuned for the stuff. I think it was a bad tank of fuel, but I see full timing when I use Husky 94. I should have some of those datalogs somewhere if you want to see them. Best guy to talk to about this stuff for a Subaru is Airboy on WSC, if you haven't already.

[Sorath]

hey man, yeah im kfarm on wsc, i had a problem with the accessport awhile ago. i talked to sunny, he hooked up his datalogger to my car and we ran 91 cobb stage 1 and the ecu pulled about 1-2 degrees around the 5000rpm mark. But i havent tried the 93 octane, if you're free and dont mind we can try and test the 93 on my car. i was supposed to get a map from sunny but hes been really busy lately and i wanted him to do it in accessport format so i can easily change maps between the accessport. But i`ll shoot u a pm.

[Sorath]

so i tried it last night, man it felt so much better, at wot its still showing 11.0 so im running hella rich? just hope i dont knock.

[benyl]

I was running 10.5 on husky 94 to be safe.

Since it is an oxygenated fuel, your O2 sensor will think it is leaner than it really is.

With the STi, I wouldn't worry about knock as much as exhaust temps.

[ShermanEF9]

Originally posted by Eleanor
I'm pretty sure GQ is right. AFAIK all gas in Canada has ethanol in it :dunno:

FLARE, if you're tuned on 94, of course you're going to knock on 91 :banghead:

Sherman, are you tuned on 94?
im n/a, and it'll program itself to run it.