What grade of gas to use??
 

What grade of gas do you use in your protege 5's? I am new to the mazda family. I used to own a VW and always used premium gas in it. Is it recommended to use premium gas in the P5? I know in the manual it says that regular gas is okay? I am hurting anything or getting any benefits by using premium?

thanks
Greg

i use 89 octain....i find the engine run's smother with it especialy in the winter time

I just recently filled up with the highest octane that we have available everywhere, 94 and it runs really smooth. Usually I go for the lowest available because of money hehe, 87 and it's not that great...... Your car won't be any worst off though if you use lower grade fuel.

The Protege's ECU is programmed to keep the engine tuned for 87 octance. It will not recognize higher octane gas and will not tune the engine to take advantage of higher octane gas. I stupidly ran higher octane gas in my Protege. Although it was a tad bit smoother when I first started using it, after a few thousand miles, the car was running slightly hotter and was hesitating. When I changed the spark plugs, they were covered in carbon! With the new plugs and 87 octane, the temperature went back down to normal and there's no more hesitation. 40,000 miles, countless gallons of 87 octane, and another set of spark plugs later, I haven't run into the same problem again!

-Jerry

I remember something in the user's manual for the 2.0L engines saying to use premium. For the 1.5L or the 1.8L it says that it is okay to use regular though...

I was told to run a higher octane

see sig

are you sure the ecu wont take advantage of 94 octane? i thought all ecu's are designed to adjust their fuel maps during regular use. i always put at least 91 octane in my moms 99 protege 1.6, but that is the recommended octane level anyways. when i put 94 octane it seems a lot quicker and i havn't noticed it running any hotter. i just changed the spark plugs yeserday and they were fine, nice and orangey with almost no deposits.

On Page 4-2 of the 2001 Owner's manual:

"Your Mazda will perform best with regular unleaded fuel having a research octane number (antiknock index) of at least 91 [(R=M)/2 method, 87]"

The manual states to USE REGULAR. My car is a 2.0L.

thank you mike, I was gonna go to my car and pull out the manual and quote it, but you saved me some walking time :D

USE REGULAR UNLESS YOU HAVE SIGNIFICANT ENGINE MODS.... :D

LOL! That's exactly what I did....somebody had to stop the insanity!! :D

Look a little bit farther down on page 4-2 in the User's Manual....

It is also on the back of the User's Manual:

Quoted from 2001 Mazda Protege Manual!! BOO-YA!!! :p
Don't believe me, then check it yourself...

I DO NOT have that in my manual.

HAHAHAAHAHAHAH!!!! The part I quoted is actually a STICKER covering up old writing. I flipped the page over so I could read the writing (backwards though) and it's what you are quoting Zeriak. Looks like they had a misprint and changed it in the manual...seems yours didn't get fixed.

HAHAHA! Perhaps you are right. I'll so bet that the 91 Octane is for the MP3 Engine.

Someone get the manual for the 2002 Protege and tell us what it says to use...

I called the Mazda Customer Service Center. They said the 2002 Owner's Manuals says to use 87+ and they said for my car I should use 87+

I think the "Special Edition" is the MP3 which probably uses the 91+ Octane Rating.

Stop the madness!!! Technically, I'm right because my User's Manual is wrong. Hehe. :D

HAHA! Oh well, I'll just use 91+ anyways :)

In my 2002 protege/protege 5 manual it says to use regular gas 87 octane gas or above.

Greg

My dealer gave me an outdated User's Manual and now I have shamed myself and my family. I will commit seppuku immediately. :eek:

Here is an excellent explanation of pinging and octane written by an ex-GM engineer who spent the majority of his time there working with engine controllers.

http://www.msgroup.org/Contrary/NEG037.html

Here's a motorcycle site that discusses the difference in octanes and power content in fuel.

http://www.factorypro.com/tech/fuel_..._vs_power.html

Looks like you can use any kind of gas you want as long as there is no pinging. I'll spend the extra 2 bucks every fill up for the peace of mind that the higher octane fuel gives me better protection against pinging.

As was quoted from the owners manual:

"Your Mazda will perform best with regular unleaded fuel having a research octane number (antiknock index) of at least 91 [(R+M)/2 method, 87]"

On most gasoline pumps in North America, the method of stating octane is (R+M)/2. Therefore, look for an 87 octane rating, not 91.

I'm leaning towards siding with Zeriak on this one... Why not spend the extra $2 per tank and have the peace of mind knowing you did all you could as far as gasoline types go? I think I'm going to put only high octane gas in my car...

I may also move to synthetic oil too... still haven't decided as of yet.

PJStyles

Why not spend an extra $2 per tank? Probably because the manufacturer spent hundreds of thousands of dollars tuning the engine to run on 87 octane.

In a recent report of fuel economy and usage by the Canadian Automobile Association (CAA), they stated: "Consumers should always use the type of fuel recommended by the manufacturer in the owner's manual. In many cases, using high-octane fuel in a vehicle that does not require it will actually decrease fuel economy."

And here's a quote from VP Racing Fuels (a division of Medford Fuel), "The key to getting the best racing gasoline is not neccesarily buying the fuel with the highest octane but getting the one that is best suited to your engine."

And answer me this... in today's world where manufacturers (particularly Japanese) are competing for the best reliability, why is it that they would tell you to run 87 octane fuel if it is going to be harmful for the engine? In fact, what they tell you to use is what is best for your engine and they have come to that conclusion through their own testing!

-Jerry

I understand that... but the Protege is marketed to the average consumer if you ask me... I don't think it would go over too well with many consumers had they put 91 octane levels as the bare minimum... then again who knows.

Not really sure what to believe if truth be told :)

PJStyles

So is that product, Redline SI, recommended? And where does one in Canada get it? And it should be used every 16 tanks of gas?

PJStyles

Will using a good fuel cleaner at regular intervals limit any occurences of knock/pinging? I don't even know what pinging sounds like since I've never heard of it before.. I'm new to auto mechanics as you can see :)

PJStyles

I guess my only question is why wait to here a knock when you can just use high octane gas to prevent it in the first place. I read the article you posted with all those details... I guess the next best solution is to run a bottle of Redline SI-1 every 6 months as you mentioned and go from there... perhaps I'll just do it every 2nd oil change.... which is approximately every 12,000km or so.

PJStyles

Hmm....lots of talk about fuel system additives and cleaners here.

And we are all quoting the manual for the proper octane gas to use?

Well, to futher quote the manual, page 4-2:

"Never add fuel system additives. Never add cleaning agents other than those specified by Mazda. Other cleaning agents and additives may damage the system. Consult an Authorized Mazda Dealer"

I believe the 87 octane gas rating, and I don't follow the "hype" of higher octane. I've used 87 since day one, and with 26,000 on the odo, I have no problems, and few extra bucks in my pocket.

But what additives are Mazda approved? Is this just "hype" to keep us visiting the dealers for fuel system service, rather than just dumping a pint in the tank ourselves?

I have not used any additives in the year I've had my P5. So - what should I do? What would my "Authorized Mazda Dealer" recommend I put in the tank?

Interesting post... I'd be interested to hear some replies to this last post....

PJStyles

$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

:D

And if it's not needed, it's simply not needed. Why pay more if you don't need it????

Okay. So I guess my question here now is, does the fuel computer map what kind of fuel I fill up with at the gas pump? When I called Mazda Customer Service the answer I got was 87 plus. How am I supposed to believe anyone these days. What's to say that the engine is really supposed to run on Mid-grade, but you can run it with regular and Mazda's marketing group says people like cheap gasoline. Let's tell them they can run crap gas in their cars so they think that they are saving money! I mean the Protege IS Mazda's entry-level (read: cheapest) car out there.

Now, one of the articles I read further up in the thread (internet link) talks about a guy saying that crap gas cost him valve work. Well, he had an imported car (an old volvo) and further down, the article says that the US has the crudest gas in the world octane-wise. Apparently lots of manufacturers de-tune their engines for US export because we simply don't run higher octane gas. Apparently Germany has 94 Octane at the pump! Our Premium to the Germans is 'Regular'.

Now, my question is, what octane ratings do they have in Japan? People with J-spec engines should be very careful with what they put in their engines. I believe that until I get a straight answer from someone, I will run 89 Octane. That seems to be the best compromise. :)

I'm not quite sure why there is such opposition to using 87 octane fuel.

The manufacturer not only recommends, but specifically states using 87 octane fuel is best for your car's performance and longetivity.

The government, through agencies such as the National Highway Traffic and Safety Administration (NHTSA) and the Department of Transportation (DoT), state through many studies that using fuel with a higher octane rating than your engine is designed for is a waste of money and decreases fuel mileage.

Highly respected groups and associations such as the American Automobile Association (AAA) and the Canadian Automobile Association (CAA) state through many studies that using fuel with a higher octane rating than you engine is designed for is a waste of money and decreases fuel mileage.

Enthusiasts clubs (who are very worried about performance and reliability), such as the Miata Club of America (the largest single model car club in the world), recommends using the octane rating your car is designed for.

So who is it that recommends using high octane fuels all the time? The gasoline companies! Those who are charging $1.92 per gallon for 91 octane premium fuel...

So, if you still insist on using 89, 91, or 94 octane in your stock or lightly modified engine which has been specifically tuned and designed to run on 87 octane, then go ahead. If you don't mind higher costs, lower fuel economy, carbon deposits, and lower performance, then please use higher octane! Those of us who would like to properly care for our cars and avoid nasty repair bills will listen to the people who regulate, design, build, study, maintain, and repair our cars.

I guess I just wont be satisfied with what everyone is saying. I'll change my gas usage to 89 octane. In the book it says to use "at least" 87 octane.

Now I know my manual is different than everyone else's manual but I think we can all agree that it says "at least 87" or "87 or higher".

Okay, so I guess the only real test to see if the gasoline you put in your car is not designed to be in your car is to look at the spark plugs when you change them. I will try to keep my spark plugs when I change them since I have been running higher octane than 87 for most of the car's operation. I'll take digital pictures and post them sometime. Now I need to borrow the girlfriend's digital camera :)

one reason that i worry about using 87 octane (although i have always used it) is that gas stations have worse gas than others. meaning that, for some reason or another (its a long explanation), the fuel does not have the octane rating that they advertise. this can cause big problems.

I have a family member who works in Alberta with the gas business. It turns out that in Canada, all gas stations get their fuel from one of 2 or 3 companies. So it's really all the same gas regardsless of where you go. SOme companies may add things to the gas once they buy it but it's still your basic 87, 89 or 91 octane fuel. Those who want to believe otherwise can do so it their own expense.

As for this over-discussed octane matter. Obviously these people enter this thread wanting to read that our simple economy cars need high octane fuel. They can, and do, read through dozens of posts containing facts and proof regarding the ill effects of using higher octane fuel than you car is tuned for. These people are looking for the opinion of one or two individuals who for some reason think 89 or 91 octane may be better, and grasp to that idea like a life preserver. IMO, it's not much different than silly ricers who want to believe that their pointless mods(spoilers, coffee cans, cutting springs) will actually add performance to their cars. These people will wade through wave after wave of proof that these things hinder more than hurt just to latch onto someone's "first hand experience" where they claim that cutting springs gave them better handling.:rolleyes: Whatever..., it's your money to waste and your car to damage.

"Ignorance is bliss"

I've decided to go the rought of 87 Octane with a Redline SI-1 bottle every 6 months...

PJStyles....

P.S - Thanks to everyone who provided feedback.

My protege is on it's 4th tank of gas right now.

I'm not sure what the dealer put in as the first tank, but I filled it with premium for the first 2 fillups.

On my 3rd fill up (the 4th tank), i tried putting in regular gas. I listened VERY carefully for any difference in "smoothness", and I detected nothing. Engine temps were also the same. $2 a tank adds up over time. I'll be using 87 octane from now on, unless I ever up my compression ratio or something, which is unlikely.

My dad takes excellent care of his cars, always uses the gas they are designed for, and none have ever had any problems. He also does not use those fuel additives.

A friend of mine had a tercel that ran to 260k miles, his family ran regular gas in it the entire time. Even at 260k miles, it sounded just like a new engine.

Well, I'm going to jump this thread because it just sparked into flame.

My POV is:
Manual says 87 octane "at least" or "or higher".
Foreign cars use higher octane fuel. Protege is an imported car.
ECU is tuned for 87 octane. How does anyone know? Did someone here program the ECU for the Protege? Does the ECU adapt to the fuel given? No one knows for sure. Post an email from a Mazda engineer or Mazda's engineering tests before you start flaming everyone who doesn't agree with your notion of which gas to use.

I personally called the Customer Service center where the CSR asked the "tech guy" what fuel to use. She replied with "87 plus". Now, this sounds kind of hokey, who is this "tech guy" anyway?

It all boils down to this. The manual and the specifications of the engine itself says to use "87 plus". The MP3 motor which if I am correct is essentially a 2.0L with a different cams is recommended 91 octane.

The choice is yours. Now that I have done a little research on the matter, I will go with 89 Octane to be safe. One step above 87 one step below 91. Sounds like a happy compromise to me. I may run some of that redline stuff in my car every once in a while anyways. Other than that, it's not like using 89 or higher Octane is like pouring diesel into the gas tank.

The MP3 gets part of its increased horsepower because the ECU is programmed for premium fuel. The MP3 does have a knock sensor and lower octane can be used. However, the engine will produce less power because the ECU is retarding the timing.

However, it is not the other way around. The standard ECUs will not advance ignition timing to take advantage of premium fuel. We've had this discussion about a year ago on the Edmunds board where a Mazda employee is a regular. He checked with the engineers about that...

The Protege is indeed a foreign car. However, foreign cars are designed to run on higher octane gasoline when they are sold in foreign countries. This is why, in general, our car's European and Asian versions put out more power from the same engine. Like it was said in a previous link, most foreign vehicles are drastically detuned for our crappy fuel.

But, use whatever you like. Except for the few months I believed the hype about higher octane, I've been running 87 octane in my Protege for over 3.5 years now and I have yet to hear single knock or ping.

-Jerry

Safe? Safe from what?

What no one here wants to admit is the psychology of this whole discussion. There is no benefit to using 89 octane in a relatively low-compression engine that is designed for 87 octane. For crying out loud - the difference between 87 and 89 is nearly negligible anyway. The only benefit is the "warm and fuzzy" feeling you get from "treating your Protege right" - after all, more expensive always equals better, right?

The same conflict exists with spark plugs - people think that using plugs with "more spark" will give "more power", and this is utterly false. I have first hand experience. I decided to run SplitFire plugs in my Miata a few years ago. I thought I was feeling a power difference, too. Then, about two weeks later, the engine starts pinging and hesitating. I changed to premium fuel, which helped for about 1 tank - then the pinging was back. So I changed plugs again, thinking maybe the "crappy" 87 gas fouled up my plugs. This time, about two days go by, and the pinging is back. I ask a mechanic I respect, who tells me that the plugs are too hot for the engine. The excess heat they generate is causing detonation - fuel igniting beore the spark, due to compression - like a deisel motor. And the extra octane gas wasn't helping.
When I pulled the second set of plugs, the carbon build-up was extroadinary - one week of use, and I had plugs that looked like they had 100,000 miles on them.

I switched back to the OEM spec plugs, and 87 octane. The car ran flawlessly from that point on.