i have a '00 ls1, internally stock. just has catback, HAI (hot air intake lol), and a jesse bubb basic mailorder tune. i mostly did it for the speedo calibration and to remove VATS and all that crap (its in my rx7), so i dont know if the fuel/timing maps got messed with or not.
anyway, am i allowed to run 87 octane? cuz i have been. the car has been running for 3500 miles now, and i have yet to put anything other than 87 in it. i know for sure i wouldnt recognize knock/pinging if it happened, so i'm just hoping its not. would i get a CEL if it was knocking? is the PCM pulling a bunch of timing, resulting in traumatic power loss?
i dont want to buy expensive gas if i dont have to, but at the same time im not trying to blow up my engine.
oh yah, and if i do fill up with 91, do i have to reset the PCM to get the most out of it, or will it learn on its own?

 

The computer will retard the timing and not throw a CEL, the motor is designed in the worst case to take 87, but the 91+ is reccomended. You could be leaving a lot of HP on the table by using 87.

BTW- Even after putting in 93, it'll take one to two fill ups before the computer decides that enough 87 is out to give you back your lost timing

 

the PCM does in fact figure out that ive upped the octane? i was wondering about that- i assumed once it had settled on an 87 setting, it would just stay there. although i suppose pulling the fuse is a faster way of gettign the same results.
well hey, if i can run 87 for my daily driving then why not. i hardly ever rev over 2k anyway.

 

Does the PCM detect Octane Boosters or Race gas.....will our cars make more power with higher octane...if so how much more?

 

dude. just run the 91. at 10+:1 you'll do yourself a favor. whats 20c a gal to give yourself another 20+hp AND peace of mind? trust the ls1 guys. they wouldn't steer you wrong, unless you're into bracket racing. come on, the guy who runs 12's says to do it. do you run 12's on 87? even in that chassis? take some pride. an lsx motor says "i'm a tuner, and i want what's best for my car" so you already know what to do. if you can't afford the good stuff then why the hell did you swap an lsx into a mazda???

 

just run the higher 91 dont risk ****** up ur motor. 2cents

 

unfortunately I've had to run 87 in my Z due to a local gas shortage. Nobody had anything but 87. I also had quite a bit of pinging. soooo Id say dont do it lol

 

how do i tell if its pinging? i know what knock is and ive read a few descriptions of what i should hear, but ive never recognized it, and i dont think i would if it was happening. btw, i wong be drag racing on 87, just driving to and from work. i hardly every go above 3k rpm.

 

I am confused. Is it 2k or 3k that you hardly go above?

 

Someone correct me if I am wrong, but I think you have the misconception that the car 'detects' the lower octane. I do believe this is not the case. The pcm detects when it sees knock and reverts to the lower octane table. So, you are actually getting initial knock and the computer is learning to use the lower octane table more often. Although it is built to handle this situation, it is still not good IMO.

 

no it's not good to use 87 and if you do you will get less mileage to the tank, so in the end it's not saving you money. My friend's LT1 TA lost 50 miles to the tank just going from premium to midgrade, think about how bad it would have been if he dropped all the way to regular 87.

 

I can't believe how cheap some of you guys are. I've seen this question posted before on various sites. It really amazes me. Think about all of the money that you spent on your car and now you think it's ok to get cheap when it comes to gas? Generally... premium gas is 20 cents higher than regular. Figure that you are going to put 15 gallons of gas per fill up. You are saving a whole $3.00 (20 cents X 15 gallons) by putting in 87 octane. Is "saving" $3.00 worth the possible risk of damage to your engine, poor performance, and decreased fuel economy? I'd spend the "extra" $3.00 rather than spending money for a rebuild.

If you are so concerned about saving money, here are a few tips:

Bring your lunch to work instead of buying fast food. It's healthier for you too.

Drink 3 Coronas at the bar instead of 5 Coronas. You'll save about $10 and be able to drive home. Or better yet... bring in your own beer. Just make sure to wear pants with big enough pockets so that it doesn't look too obvious. Oh... another tip... make sure to sneak in beer that the bar actually sells. Bringing in beer that the bar doesn't offer is a sure fire way to get you thrown out.

Don't over-tip the waitress at the bar because she it hot. You're not going to get into her pants anyway.

Don't waste your money at the strip club. You're not going to get into a stripper's pants either. And even if she was good to go and takes you back to the "Champagne Room"... why risk the possibilty of your di(k falling off?

Don't spend $20 on lottery tickets when spending $1.00 will net you the same results. You're chances of winning don't increase because you spent more money on tickets... really... it doesn't make a difference.

Rent a movie instead of going to the movies. You won't have to spend $15 for pop corn and a drink either.

 

I dunno if he's cheap, ....he explained how there was a shortage in his area and all they had was 87

 

The person that posted the thread didn't state that... there was another person that stated that there was a shortage in his area and he had no other choice. He also stated that his car started pinging and he also said not to put in the 87 Octane.

 

Ahh correct, sorry bout that...

 

i'm just asking geez. its back on a 92 diet now. i drove it 2600 miles (texas -> oregon) on 87 thinking/hoping it would save some money (crusing at 2k the whole way). i figured it would be fine cruising. that got me in the habit of filling with 87, and it just recently occured to me that maybe the PCM cant compensate, although i assumed it could. thats why i started the thread.

 

It just amazes me that I see people asking this question on many boards and it's really not worth it. My dad even tried going with a lower grade octane with his Cadillac ETC. I told him not to... it's not worth it for the various reasons that I stated. Guess what? He told me, "You were right. I lost performance and mileage. I didn't save anything." It's fun showing your parents that you know a thing or two.

 

I run 93 and Sunco 94 when I can, with my tune I can run 91....

Peace of mind.....

If ya don't want to be paying for expensive gas then its time for a beater...

Its only like .20 more a gallon, over a fill up its not a whole lot more.
Its around 2.00 more a fill up or so...