arsenal21

Significant powerloss will be felt!! Ya I know what the manuel says. And its true. I'm so mad at myself for doing this.

I had to get a few gallons of gas for my lawnmower yesterday so I decided to get 89 and fill up the lawnmower gas can. Then top off my 1/2 tank of 91 with the 89, since I figured it'd be the first time I tried doing this to my SS. BAD IDEA. The car is so slow now. Gotta burn through this tank as fast as possible.

astrocrep

Nothing but 93 in mine... and no chance of anything lower.

-Rich

JamesBrown

Hmm, thanks for the info. I'm a poor college student and was thinking about using 89 or 87 until i get a little $$ since i dont drive hard, but if it's that bad...i guess i'll just spend a little more.

Roger@AEM

Bad idea.....lower octane gas will cause pinging and detonation. I'm sure the ECU will see the knock and start pulling timing, which is why you lose power.

You can still damage your engine, and if they find out you put in lower octane fuel, I'm sure it wont be covered under warranty.

player_1

I know what you mean, it's ultra 94 from every time

Woodio

I fill mine with midgrade, and I can't tell the difference...

spooler

this is something that I had a feeling of.. definately timing will be pulled if you run a low grade gas on a boosted car.

BullDog71ss

I use 87 for normal, every-day driving then switch to 91 (the best we get in Az) for any kind of racing or when I go on my night-time cruises.

I don't notice much of a performance increase from jumping to 91 from 87 though. I've also never heard any pinging what so ever.

arsenal21

It dosn't have the pull it usually does as I get high up in the rpm's and boost. There's no pinging or knocking. Just the feeling of SLOW. It just wont get up and go like it's usual self. The manuel says that it will run fine on the lower octane, and that the driver will feel significant powerloss. I just didn't know how bad the powerloss would be.

chevyss

this is totally true!! i just encountered the same issue with my ss/sc....i usually put in ultra 94 but with recent gas prices decided to put in exon 91 and WOW what a difference that made!! i can just feel the lag in power loss especially in higher rpms...i feel like sifining the shitty gas out putting some better octane back in..i am now a firm believer in running high octane fuel for a reason...i never new it could be such a noticeable difference...i wonder if i go by some octane booster if it would help it out... if not, i have another 220 miles of poor performance, lets just hope i dont get challenged during that time.

BullDog71ss

Heh, I wish I could gas up with some 94 from the pump. Az sucks for quality gas...we just don't have it available. Maybe It's time to take a trip to the airforce base for some AV gas. Either that or I need to make some homemade 94.

I ran my 14.88@95 mph on half 91 and half 87. So what is that...89 octane?
That was when it was 102 degrees out as well. I bet with better fuel and cooler temps it would go down to a 14.65 or so.

97cavie24ls

ive got the CD that come in the ion's , and there was a short section for the redline's , and it mentions using 87 , and for the most power to use 91

but it also mentioned that switching from 87 to 91 would take 3 tanks get get the power difference between the 2


my idea on this has always been the 205 hp rating was done on 87 , and on 91 is why alot of you have been seeing 200 + at the wheels

97cavie24ls

there is pumps with 101 , but before the whole gas rip-off it was 5.49 a gallon


ive been mixing it with the 91 in my cav , id be using straight 101 , but the 70 or so to fill from empty would kill me , lol


and yes i have reason to be using high oct fuel , my cav is s/c'd also

BullDog71ss

Would it really take that long for the computer to adjust for the higher octane? If so then my switching to 91 for a night of racing is pointless for performance besides negating any ping that might occur with lesser gas.

BullDog71ss

Yeah, there are a few in town. But they are FEW and FAR between.

Frenstall

I run 93 in the summer. I'm going to run 87 in the winter when less power is better (I can spin in the snow just as good with 87 as I can with 93)

phxSS

Why the hell would you put less than premium in your car anyway? It's usually only a $2 difference for a full tank vs. regular. i don't see how saving $2 is worth it.

Woodio

Because I can't tell the difference...

Darksun

Hmm....not a bad idea. And yes there is a difference from even between 93 and 91 the way i tested it out was racing my friends g35 six speed coupe from 2nd gear roll pulls and even on a 1/4 tank of 91 octane he would just pull away easily. We already knew i should be beating him since we've raced before So that told me it was the gas. So I ran that gas out same night put in a 1/4 tank of 93 octane drove around from a while did the same test with 40 roll pulls and was even with him at first and by the 4th race was was pulling away slightly. I was ganna make a post on it but I see theres this one instead. Oh yeah car didn't feel any differnt on 91 octane but the proof was in the pudding when my friends G35 was walking all over me like i was a single over head cam 1.6L civic. And for those that don't Think its true than oh well keep putting in lower grade octane it doesnt hurt the car but i wouldn't go trying to win a race on it.

phxSS

^^exactly. The butt dyno doesn't tell you anything. You will know, when you get beat by a 2.4 SS

Point is, why would you want your computer to retard your timing, and put strain on your system just save $2??

Zonomar

87 is recommened fuel from GM Canada

I use 89 just because - but the price diff may grow if no new refineries are built any time soon.

SuperSS-Boss

One thing i have learned over the years is the tuning process that each vehicle goes through. If you get a programmer, this will help considerably. The ECU does respond to the Gas you put in it, to help against pinging and detonation, but if you are able to re-tune it with a programmer, this again is your best solution if you are needing to put in less octane gas. I know these cars are pretty new, and never trust a first off programmer, they are most likely thrown together for fast production, a better one will come out 6-12 months after the initial testing is done, and most testing is done by (us), trial and error.... then a new and better product comes out... I can tell you i have saved thousands of $$$ for waiting that extra 6-12 months to see how others do with new products.. My vehicle is not a guinny pig, and i try my best to get the best product for the best price.

But, on topic i would only put what the book recogmends, and nothing less unless i have to, and NEVER hard driving.. I am sure the ones that have done this and have have no problems, you shuold feel this over time, and maybe not right away. Constant use of unregulated(+/-) octane can harm an engine, and cause problems down the road... Combining/mixing gas is a no no too, i have read. Cant remember for the life of me why the major cause of that is though... There will be those who will disagree,a nd agree with me, so to each his own... LAter

phxSS

If you own a 2.0 Ss, and you think GM "recommends 87 octane", you need to read your manual again

97cavie24ls

the info CD i got from the ION was in southern california , and it said 87


i do agree to why would you , but it is nice to know if your on a road trip , and its all you can find


atleast youll only loose some power and not the motor

player_1

Gm does not recommend 87 Octane it states that you can safely use 87.