I HAVE to ask!!! answer me this guys!!!

[tvc3-gtz]

I have a 1990 Beretta GTZ q4 H/O, and I have been running it with premium octane (92 & 93 octane) gasoline since I have bought the car. Is this necessary for these engines? is there a difference between standard octane fuel and what I run my q4 GTZ with? I always wanted to ask this but never had the chance.. You guys know better than me about a lot of things.. I wanna see if I am wasting my money or taking good care of my car.. any input will be greatly appreciated.
- Tom

[speedy]

theres a reason it states in your owners manual "premium fuel recommended" and it also says on your instrument cluster "premium fuel recommended", if you run 87, prepare for it to tick, it will run, or so ive been told, it will just have a tick. best advice i can give you, if you like your quad, stick with 93 for the extra $5 per tank. its worth it.

[3X00-Modified]

You have high compression and aggressive timing that's how a quad makes its power. Running 93 is the only way you can expect to run smoothly and ensure long engine life.

[SuzukiGhostRider]

You have high compression and aggressive timing that's how a quad makes its power. Running 93 is the only way you can expect to run smoothly and ensure long engine life.

This. And also the only way you'll avoid fuel knock in the engine. Running lower octanes will kill power, cause fuel knock, and make the car run like crap. It's DESIGNED to run on 91 octane or up.

[tvc3-gtz]

so it's a goos thing I havve never gone lower than 92/93 octane... nice.. well I'm glad I'm doing it all right. thanks guys

[pghturbo88]

My LeBaron turbo takes minimum 91 octane as per the owner's manual. I estimate how many gallons I will need to put in via the mileage computer on the car. If I need 9 gallons, I swipe the credit card, and put in 6 gallons of 93. Then I swipe the credit card again, and put in 3 gallons of 87. So it's essentially two parts 93 octane to one part 87 to get 91 octane gas (do the math). I have found it is cheaper to do this than to select the 91 button, if one is available. I do not notice a difference in performance or mileage compared to running straight 93 octane, and have been doing this for years in my Mopar turbo with no problems. Saves $1 to $2 per fill up. Learned this trick from Tom and Ray (Click and Clack the Car Guys).

[SuzukiGhostRider]

Personally , I've never understood taking a chance with your engine to LITERALLY as stated save $1 to $2. Is it really worth the inherent risk to save a couple bucks for what could cost hundreds or more to fix later? Or get 50k to 100k less miles out of your motor?

[88gtz]

Personally , I've never understood taking a chance with your engine to LITERALLY as stated save $1 to $2. Is it really worth the inherent risk to save a couple bucks for what could cost hundreds or more to fix later? Or get 50k to 100k less miles out of your motor?

I agree, if it says premium fuel I put the highest octane available. Just my opinion though

[pghturbo88]

Personally , I've never understood taking a chance with your engine to LITERALLY as stated save $1 to $2. Is it really worth the inherent risk to save a couple bucks for what could cost hundreds or more to fix later? Or get 50k to 100k less miles out of your motor?

Just sharing a different point of view -- agree that people can spend their own money as they see fit, as well as choose what information they wish to use from internet forums. I do not own a Quad, but I too have a sticker on my LeBaron's fuel door that reads "PREMIUM FUEL RECOMMENDED." My Chrysler owner's manual says to use 91 ocatane fuel, and I use 91 octane fuel. Period. In no way do I advocate running lower-than-specified octane fuels as a cost saving method, as I 100% agree with SGR that doing so will certainly result in engine damage. I have been doing this (mixing 93 with 87 to get 91) since the early 90's, and at 155K miles, no problems, no knocks, no pings, and 100% performance (or as much as you'd expect from a small Chrysler 146 hp four banger). I do not believe that spending extra money on the extra octane buys me any sort of insurance, and I have a rock solid 23 and 1/2 year old engine as proof. My opinion is that if you run the octane recommended by the manufacturer, which I read in this post is 91 for a Quad, you will be fine.

PS Conservatively estimate save $1 per fillup (buying 91 instead of 93), 24 fillups per year times 20 years = $480 -- that's real money. Save $1.50 and it's $720.

[DTMAce]

Then you have idiots like me that bought 92-96 octane fuels for over 212 thousand miles of driving with a car that didn't need it. LOL

Mostly because of ignorance, but it always appeared to me that the car simply ran better with the higher octane and got better mileage. Maybe it did, maybe not, but it wasn't required that's for sure. It certainly didn't hurt it, just made it harder for the engine to burn the fuel is all.

The only reason to run the higher octane fuels for higher compression engines, is to prevent pre ignition (or spark knock). Will that damage your engine? Most likely not in the short term, but continued use over a long time could increase wear of certain parts of the engine, like rods/bearings. Mostly from the pre-ignition keeping you from having a smooth running engine. Performance would suffer too.

So.... Just run the right fuel. That way you won't have to worry about it.

[SuzukiGhostRider]

That's one thing I love about having a debate with you Pghturbo88. You always conduct yourself like a gentleman. (not sarcasm)

[pghturbo88]

That's one thing I love about having a debate with you Pghturbo88. You always conduct yourself like a gentleman. (not sarcasm)

Thank you! I always believe that you catch more flies with honey than with vinegar, and that to come on here and flame people accomplishes nothing. Hopefully others notice the way that we discuss things and follow suit. You'd probably find it hard to believe that I agree with you more than I disagree. However, I just want to provide an alternative point of view from time to time. People should be thanking YOU for all of the time you take to answer their problems, many times from a newbie that starts the post with HELP!

[tvc3-gtz]

i'm glad that was answered

[SuzukiGhostRider]

That's one thing I love about having a debate with you Pghturbo88. You always conduct yourself like a gentleman. (not sarcasm)

Thank you! I always believe that you catch more flies with honey than with vinegar, and that to come on here and flame people accomplishes nothing. Hopefully others notice the way that we discuss things and follow suit. You'd probably find it hard to believe that I agree with you more than I disagree. However, I just want to provide an alternative point of view from time to time. People should be thanking YOU for all of the time you take to answer their problems, many times from a newbie that starts the post with HELP!

Thank you. I do what I can to help. And I have noticed we're usually in agreement on most matters.