I know I'm going to engender a plethera of negative responses from this, but here goes. About a month ago, I asked my wife to fill up my '04 coupe. She inadvertantly filled it with 87 octane, to my chagrin.

However, I saw no difference!!!! The mileage remained the same (24-28 mpg), there was no predetonation nor pinging, no loss of power, no overheating. and no dieseling when the key was turned off.

In light of this experence, I am continuing to run on 87 octane.

While I realize the savings amounts to roughgly $120/year, why pay any more than necessary if all other variables are equal?

Don

 

Cuz she's yer Baby!


Have seen posts on this from waaaaay back. Forget what the final outcome was.

 

I don't want to "flame" you, but you DO want responses or you would not post at all.

Ok, so...

Why not go to your local oil change shop and tell them to use whatever oil and filters that will result in a $35 oil change?

What I mean is - how far are you going to carry this struggle to save money on that car? Where do you draw the line now that you are throwing out the manufacturer's recommendation on fuel?

MY PERSPECTIVE: I was told before I bought this car that maintaining it was going to cost more than I was accustomed to. I thought long about it, and when I was done thinking, I was prepared for $120 oil changes and sets of tires that cost $1,000.

REALITY: Gas costs 35 cents per gallon more for the XF than my truck. *yawn* Big Deal.

 

Our cars were designed for a minimum of 91 octane for a reason. You are taking a chance of major detonation (engine knocking) but of course the car must be pulling timing like crazy. It's your car and you can do what you please. Good luck!

 

Its a modern car its not from the 80's 4 points on octane wont matter .....cars are alot smarter these days

 

Cars may be more advanced now than back in the day's, but still you are asking the the car to perform more things than it was designed to do, thus causing premature wear out on the components. The car was designed to burn a higher grade of fuel for a reason and thus the ecu was tuned to those parameters. Taking a chance on destroying your car to save $120 a year versus the cost to replce worn out componets does not make any sense to me. I know from working on SAABS, customers using the higher octane gas was much better and the cars had less drivability problems than those who used the cheap 87 gas. I have always used the better gas with whatever car I drove that required it. And even in my Durango 4.7 there is a big difference in performance, just from 89 to 91+ octane, and thats all I use in it now. But you do what you feel is best, but I am sure you will find a lot of us xfire owners use premium gas all the time.

 

its all about timing....the car will compensate for your failure, to a point...if you aren't going to keep it forever, the use whatever, even walmart oil changes...there will be more parts for the rest of us in the future, 'cause this car will wear out faster...if you are going to keep it, then maintain to specs...it won't compensate forever...leaning out, burning hotter will take its toll down the road...

 

You were right Don!

 

Don,

Don't miss this thread: https://www.crossfireforum.org/forum...tml#post430233

Read the WHOLE thread - this link will take you to my post, but that isn't what I wanted it to do. I wanted it to open at the first post.

I hope my responses are not "negative".
I don't want them to be.

 

I don't see were 87 octane would be a problem. Unless of course you plan to drive the car.

cool weather and some 93 octane in the tank already, you might have gotten by OK. Also note that the sign on the pump says "minimum" octane. The tank could have been holding higher the day she filled it.

Finally, I have to ask, You really trust a woman's judgment when it comes to your car? Are you sure it is a good idea to let her be right on this? I mean it's a guy thing to be right, stubbornly so, especially about cars and machinery. Even when we are wrong. It's like a law of nature or something

What's wrong with you?


roadster with a stick.

I know I know, sexist remark. Now it's my turn to get the burn.

 

Everyone is so dramtic on this topic.....I havent had any problems runnin 87.....I better get a fire suppression system on my car before it blows up .....lol

 

OK Franc I take offense to the female remark!! LOL... I'd pit myself against most men when it comes to knowledge about vehicles, their performance and maintenance. I'm gonna have to spank you when I see ya!!!

Deb

 

Let's see, 20 cents a gallon cheaper, so $3.00 a fill up. Gee I could supersize my coke next time I eat at the golden arches, and buy a pack of chewing gum...

I'd have to agree, in the long term I'm thinking you will have stepped over dollars to pick up pennies.

The price of admission to the whole sportscar schtick is more than just the price of the car you know (this was recently pointed out to me when I grumbled about having to order winter tires & wheels)

Oh yeah, and Franc...my wife found us the Crossfire. I was looking at Z-3s and Z-4s, so I would be inclined to accept her judgements on cars, as this one turned out pretty solid!

 

The point is, the car is designed to take advantage of the higher octane, unlike most other cars, where it would just be a waste. Can it run on 87 octane? Absolutely, but not at what it's capable of. If you are so interested in getting by as cheaply as possible, then the Crossfire was the wrong choice. You should be driving a used Corolla.

 

he asked, 87 octane, maybe, maybe not, the car will compensate, and yes, for those of you that don't care...burn it...you won't be keeping it forever as some of us will...so, some will take all better care of our cars, changing the oil early, air filters, while others don't care...it runs fine...and you are right. But it is taking its toll. Running lean, means running hotter, not in the sense your temperature gauge will show, but what the engine endures. These cars have a very good brain and they will compensate, that's why MB runs for so long...but it doesn't make it right, just makes it so so...a lot of people treat their car that way...its just a thing to drive until its time to try something else...but our toys, we seem to take better care of....so everyone is right on this one...just depends which side of the car lift you are on...

 

Don;

Besides fuel advice, you may consider a pair of reading glasses....................huge fonts yeech!

 

Every mechanic I have ever spoken to has told me to abide by the recommendation from the manufacturer, they have hundreds of thousands of hours in torture testing every part of the automobile and make this recommendation for a reason.

I bet if you took a look at some injectors from someone using 87 for 30K miles and someone using 93 for 30K I bet it would look like the difference between a smokers lungs and a nonsmokers lungs. Dramatic, maybe - accurate, yes.

 

But can you really trust those engineers? Would it not be just as good an idea to find out what your brother in law (they guy who fixes lawn mowers and works part time for the local tree service) thinks?
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Sarcastic? Yes. But you get the point.

 

If you drive 12,000 miles a year (and I think most on this forum drive considerably less than that), you're talking less than a hundred bucks a year, or $8 a month to run Premium vs. 87 Octane in your car. Sheesh...what next - get some deals on used tires and batteries? Don't drive over 55 on the highway? Hey, I know...just park it in your driveway and don't drive it at all...think of all the money you'll save !

 

The detergents in the fuel will determine the difference you see in the fuel injectors. You will see in data logging and on the head and top land of the piston or your valves/valve seats and your spark plugs if you run to low of octane and it starts blowing up microscopic parts of the engine internals. The Octane number is nothing more than a numerical rating for the fuels resistance to preignighting or knocking or pinging with higher numbers equaling better ability to resist it. On lower compression engines, you can typically get away with using a lower octane fuel because the chances of it preignighting are much lower than if all the variables were the same and it was a higher compression engine. This is why the SRT has a lower compression ratio than the NA. If we both shared the same 10.5:1 we'd have to run a much higher octane fuel because of the higher combustion chamber temps and the fact that we're already jacking the intake charge temps up when it goes through the SC.

Long story short, you might not hear the damage now but you will if you keep doing it long enough. Use the recommended fuel for the car