Premium unleaded only??

O.K. I really must know do you HAVE to put in premium unlead fuel or is it just to get maximum performance out of it. I really love the SVX and want to buy my unlces so any info would be great to have. Email is snake_1985@yahoo.com if anyone has any helpful info. I will also be visiting this page to see any replys. Thank you

[Seraph]

You can try 89 once in a blue moon(when the moon is deep purple blue) but it will only take 92+ octane. It says so on the manual and I have put in 87 once. The car nearly died and the mpg was really hell.

Lwin

I'm curious to know what the effect of increased octane levels have on the performance or explosive characteristics of gasoline. The way I imagine it is this: the higher the octane, the more difficult it is to ignite the gasoline.

In a high compression engine the gas inside the combustion chamber has a higher tendency to explode prior to actual ignition by the spark plug as a result of the heat created by such high compression.

Therefore, by using higher octane gasoline, you reduce the chance of "detonation" in a high-compression engine. As I recall the ej33 has a compression ratio of something like 10:1 right? That's relatively high in my book. Granted it's not an F1 engine or anything, but it certianly classifies as a "high compression" engine.

Am I on the right track here? I'd love to be able to give this explanation to people and feel like I'm being honest.

-Adam

Sounds about right adam. If you were to run 87 octane without any fancy computers in the way, you [could] end up with engine knocking. In theory, the SVX will notice that and retard the timing of the spark to keep the engine from blowing itself to bits. This makes your car much less fun... and even after you've put 91 or 93 in, the engine computer will still be rather confused without a reset (as I understand it, haven't tried it myself).

[lee]

Adam,

You're correct that higher octane number in simple terms means harder to ignite. However, it's not just compression ratio, but also combustion chamber shape and material present that determines the number necessary. For example, older cars/motorcycles with carbon build-up in the combustion chamber sometimes need a higher octane to keep from "knocking", or experiencing pre-ignition. Pulling the head and cleaning it up will restore the use of lower octane number - old British motorcycle tech manuals refer to this as de-coking. So all you need is sufficient octane number to stop pre-ignition. That's why use of higher than required octane number fuel does nothing for you except lighten your wallet.

I'm not a chemist, but octane is one of the hydro-carbons like methane or propane. I was once told the octane number originated as a simple measurement of how much Octane there was in the gasoline mixture along with the various other "anes".

http://www.osbornauto.com/octane.htm

[Ron Mummert]

Look at it this way - The difference between 87 & 92-93 octane is about 10 to 15 cents per gallon. A 15 gallon fill up every week costs you an "extra" 2 bucks or so. Instead of supersizing to that fast-food double greaseburger, monster fries & 98 oz. drink, save the cash, stick with the regular size dose of chlorestorol, & feed the SVX properly. You may ultimately lose weight, give the car less of a load to haul & improve gas mileage.

Ron.

[Seraph]

Originally posted by Ron Mummert
Look at it this way - The difference between 87 & 92-93 octane is about 10 to 15 cents per gallon. A 15 gallon fill up every week costs you an "extra" 2 bucks or so. Instead of supersizing to that fast-food double greaseburger, monster fries & 98 oz. drink, save the cash, stick with the regular size dose of chlorestorol, & feed the SVX properly. You may ultimately lose weight, give the car less of a load to haul & improve gas mileage.

Ron.

Well said!!!!!

I'll tell you what annoys me. People who are so 'tight' with money that they will actually make a big deal out of saving $1.50 on a fill up. I must be living this lavish lifestyle, because I always purchase the highest octane available, except when it's lawnmower gasoline. The higher octane gasoline contains too many additives which usually burn too hot for a standard 4 cycle lawnmower engine, which greatly inhibits the lawnmower's lifespan and performance. But anyway...I mean...come on...if you're really that concerned with saving a $1.50, take a 3 minute long shower instead of a 15 minute and run the air conditioning only on 85+ F days in the summer. It's been my experience that vehicles perform better with the highest octane available. Oh and stay away from Sunoco gasoline. Their gasoline is cheaper because they use a different (less expensive) additive (I forget which one at the moment) than say BP. My own experiences, as well as those of my friends have not been favorable. You will pay cheaper price at the pump, but your gas milage and engine performance will suffer greatly (if you pay attention to that sort of thing). Aside from BP, I've been using 76 gasoline lately too without a problem, but I have no information regarding their gasoline. The mechanic I used to work for told me their gas was 'too new' for him to know anything about. Maybe someone on here has brand recommendations/information?

For argument's sake:

Let's say that for the rest of your life (we'll estimate you're going to live another 70 years) you'll be driving a vehicle which is fully capable of running on 89 octane gasoline.

Now for argument's sake let's assume that gasoline prices stay exactly the same for the rest of those 70 years.

We'll set 89 octane gas at $1.30 a gallon and 91 octane at $1.50.

Now let's say you need to put 10 gallons of gas in your car each week... That's 13 bucks a week if you just give your car what it needs, and 15 bucks if you treat it well.. If you go through life pumping premium into your car, you'll have spent $54,600 on gas. If you feed it 89 octane you'll have spent $47,320. That's a savings of $7,280 over the course of your lifetime. Feeding a car that only needs 89 octane gas 91 will probably only squeeze an additional 10,000 miles out of your motor, but 7 grand will buy you a new engine.

-Adam

An extra 10,000 miles can be the difference between having to buy a vehicle now, when the bank account is low and you're getting ready for a family vacation, or buying it a YEAR from now, after you've received your nice promotion and are now earning the big bucks. Or perhaps vice-versa?

Basically it's a game of 'what if.' No one can predict the future, and if you're more comfortable saving $2 a week than prolonging your engine's life, go for it.

However, you may want to take into account how many of you have problems with your svxes as opposed to how many of you use the lowest octane possible. There probably will be a coralation.

I only use Texaco gas in my car now. I was switching between Texaco and 76 every week but the last time i used 76 my car ran like complete crap so now I don't.

Yeah, I really havent heard anything about 76 gas really. What I find odd is that in the couple of months I've been checking this board out, no one has really mentioned Gasoline brands. Of all things to mention on a car posting board, I'd assume that would come up. There should be a website out there that rates and reviews various brands.

[SVXMAN2001]

Only Mobil for me

[wasions]

The cheapest 91+ octane I can find. <=== (Scrooge)