Are there any problems with useing the octane booster and regular grade fuel in an 83?

The manual says it needs grade 90, as measured by the R methoid. All the pumps are in the R+M/2 methoid. What does that work out to in the R methoid????

If it's a higher octane than regular gas, can I just run the regular with octane booster.

The reason I ask is there is a 10 cent diffrence between the grades. With a 20 gallon tank, premium costs me $2 more than regular. A bottle of octane boost for a 20 gallon take costs me like 78 cents, plus tax. One bottle should take it from 87 up to 92 octane, even better than premium.

 

"Are there any problems with useing the octane booster and regular grade fuel in an 83?"

"The manual says it needs grade 90, as measured by the R methoid. All the pumps are in the R+M/2 methoid. What does that work out to in the R methoid????"

R is Research Octane Number or RON, M is Motor Octane Number, or MON. These are two different ways of measuring the octane rating, or knock resistance, of gasoline. There is usually 8-10 numbers difference in these two ratings for a given gasoline mix.

This means that a fuel that is 87(R+M/2) will be about 82MON and 92RON. These numbers will actually vary up or down a little for different blends, but are pretty close.


"If it's a higher octane than regular gas, can I just run the regular with octane booster."


You can run the regular fuel WITHOUT the octane booster.

"The reason I ask is there is a 10 cent diffrence between the grades. With a 20 gallon tank, premium costs me $2 more than regular. A bottle of octane boost for a 20 gallon take costs me like 78 cents,
plus tax. One bottle should take it from 87 up to 92 octane, even better than premium."


WRONG!!

Octane booster are a blatant rip-off. The ads are usually "correct", but are VERY misleading. The ads tell you that their particular brand of crap "will boost octane rating by 2 - 7 points!" Sounds good, right? What the ads DON'T tell you is that an octane point is a TENTH OF AN OCTANE NUMBER!
That's right - the ad just told you that their product will change the tank full of fuel from 87 to 87.5 octane! Wasn't what you thought, huh?

There is NO commercially available octane booster that will change regular to premium! NONE!

Bottom line - if your car needs 90 or 91 RON fuel, today's regular will be fine, and is better than premium.

 

Let me get this straight, you're trying to save about a dollar on a tank of gas??? A dollar???

C'mon now. If you want to save a buck or two, driving a 928 isn't the way to do it. A Civic would be an excellent choice.

 

I guess the question for Wally is whether there is any tangible benefit to using premium over regular as long as the recommended octane is achieved. I view the "benefit" issue from 2 perspectives (at least).....(1) will the engine be less susceptible to some form(s) of damage, and (2) will the engine perform better.

I admit, I thought that I needed premium 93 RON all the time. This is the first time I noticed the difference between MON and RON <img src="graemlins/c.gif" border="0" alt="[ouch]" />

You're lucky if the difference is only $.10 between regular and premium. In Michigan it's more like $.20 or $.25 cents more for premium.

 

Big Dave,

You're lucky you don't live in LA for a couple of reasons, gas prices being one of them. Higher than most areas.

Premium I think off the top of my head is between $1.60 to around $1.90 a gallon.

Wally,

[quote]Bottom line - if your car needs 90 or 91 RON fuel, today's regular will be fine, and is better than premium.<hr></blockquote>

I'm running premium @ .20 to .30 cents over regular...Doesn't hurt the beer fund too much however, is premium pump 91 octane over kill?

Tim
<img src="graemlins/yltype.gif" border="0" alt="[typing]" />

 

I know you have heard it all before, but it's like picking a scab you just can't leave it alone..... we're about $5 per gal here in the UK . Think yerself lucky my lad!

Cheers
Dave

 

Question: Don't all the gas station/companies use the same measurement now (at least in Canada and USA), I mean there is both but don't they use the same common octane rating at the pump for consumers? Up here, we have available 87 (regular), 89 (extra/premium), 91 or 92 (super) and 94 (Super Duper or what ever they call it: its only available at Chevron). I've been using 92 but... are you saying that say 89 is more than sufficient and won't hurt the car? Its not the money to me, I just don't like to waste money on higher octane if it doesn't make any material difference.

B.

p.s. Are there differences between highway or city driving when using a fuel octane type?

 

Originally, in most of the world, there was RON. All owner's handbooks, all consumer specs, etc., were in RON.

The oil company labs used MON - not much of anyone else.

Everyone was happy.

The US Federal Government suddenly decided that instead of the RON that everone used and was familiar with, and all the pumps were marked with, that they needed to change. They didn't change to MON, which was at least an existing standard. They changed to their own "standard", which is (R+M/2), or the average of the existing standards.

So ...

First, find what the manufacturer said that your car needed, and be sure that you know whether the spec is RON or (R+M/2). If it is RON, then subtract 4 or 5 octane numbers to translate to (R+M/2) ratings at the pump in the USA and Canada.

If Regular (87 R+M/2) is specified, there is no gain in going to a higher octane.

OCTANE IS A MEASURE OF KNOCK RESISTANCE. Period, stop, end of story.

If your engine does not knock (detonate) on regular, you will gain nothing on premium ....

EXCEPT

For those cars that have knock sensors. If your car has knock sensors, AND specifies Premium, it might not knock on Regular, but you will be losing power as the knock sensors tell the ECU to retard the timing.

 

Well, it's 20 cent between regular and premium, and 10 more cents between premium and suprime.

Well, since I can use regular 87 octane with out hitch, I'm happy. :-)

For those of you that scof at no wasteing a dollar a tank, think about how much gas you buy in a year. Multiply that, and then immagaine your a college student. 52 weeks = 52 tanks = 52 dollars...

52 dollars is a timeing belt, plus a little bit. 52 dollars is a christmass gift to someone special to you. 52 dollars is 52 dollars.

I don't approve not spending money when you should, but I don't approve spending money when you shouldn't.

If I wanted a G*D D**N Civic I would have bought a G*D D**N Civic! I wanted a 928, so I got a 828.

Now to see where I have to spend the money, and what I don't...

 

Thanks Wally...

That's kind of what I thought but wanted to confirm. My 88 of course, has the knock sensors and new ones at that so I'll continue using premium.

ViribusUnits...

Think I got the spelling right? <img src="graemlins/c.gif" border="0" alt="[ouch]" />

I agree, <img src="graemlins/icon107.gif" border="0" alt="[icon107]" /> just because you've bought a 928 doesn't mean it's a crime in trying to save a buck. I'm sure most of those here that own 928's are not any more well to do then the average person owning a Honda Civic so feel at home and enjoy your car.

We all know how cheap <img src="graemlins/oops.gif" border="0" alt="[oops]" /> most 928's can be had for but maintaining and running them is a different story and I’m sure some of us make sacrifices in other areas for the privilege of doting on our sharks.

Cheers,
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
Tim

 

tdelarm Yea, you got it right. I wouldn't be insulted if you screwed it up though. It's jsut a hanndle. Heck, make it VU if you don't like the whole name. I shortened it from K.u.K. Viribius Units....

According to the shop sevice manual, my 83 928S 4.7l engine needs 91 RON. Accoring to another page for the 80 4.5l: RON/MON/CLC 91/84/87

Is CLC the (R+M)/2 methoid?

Anyways, the way it's looking, 91-4 = 87. I can get away with regular. 104 dollars here I come!

I've noticed that with my car there is no way i could justiry the cost of maintaining it, w/o putting it under the hobie catagory. As a hobie, it's a "tinker" car. My toy, so to speek. As such, I can put it under the budget as transportation, and hobie. Plus I cut out money, because I do the work myself.

Under those conditions, the Lawn Ornamate doesn't look bad!

 

I'll repeat my story about octane from a previous thread.

Seeing as how my car came from the PO without a catalytic converter (for once I can't blame him- this is an S2, built for Austria without a cat), I decided to see if higher octane than the 93 that Chevron was pedaling here in O-town would work better with my 10.4/1 compression. So I threw a five gallon can in the back of my truck and drove to the airport....where I managed to procure 5 gallons of 100 low-lead aviation gasoline after showing them a pilot's license.

With the shark's tank nearly empty, I added all $10 worth of the blue fuel. Cessna-like fumes spouted from the tailpipe....but that was about the only difference, at least at first. I noticed no change in power whatsoever.

However, after a day or so, I started noticing a slightly rough idle, and it seemed like the car was actually down on power a bit. Growing nervous, I proceded to the nearest Chevron and filled the tank. The car ran noticeably better after this!

What happened? I suspect that the excess octane actually caused average cylinder temperatures to be too low, contributing to deposits on the plugs. This situation was probably aggravated by avgas' lack of detergents. Voila; less power and worse performance...

N!
'85 S2 5 Speed

 

The original U.S. government body that referenced the (R+M/2) spec was the Cost of Living Council - CLC. They disappeared from the scene pretty quickly, but a few early '80s references cited them.

Yes, CLC is (R+M/2) as referenced on our local pumps.

 

The owner's manual (see fuel recommendations) explains the octane rating and what is required for your model. My 87 S4 requires a minimum of 90 octane using the R+M/2 aka CLC rating method according to the owner's manual. A sticker on the inside of the gas cap filler door shows a 91 octane R+M/2 requirement. Since I've never seen 90 octane gas I always fill up with the 91. Your owner's manual and possibly somewhere around where you fill your gas tank should provide you with this same info for your model.

 

No Dice there.

My car didn't come with an 83 owners manual. Someone lost/destoryed it. It did have a photo copyed 86 manual, but thats no good for an 83.

The local dealership doesn't have any, and isn't expecting to get any. 928 intl doesn't have any 83 manuals, and don't know if they'll get any more. The dealership made me mad, so I don't know if I'd buy it from them if they had some.

There are no markings in the gas tank area that I've been able to see. The flap that cover ths gas cap on some of the cars I've seen doesn't exist. I think even the "unleaded only" sticker fell off. No dice there.