Pointless rant about regular vs premium fuel - Page 4

dcarrb · #46 10-18-2007, 12:47 PM

Quote:

Originally Posted by eviljay

I always run premium because I love my car and I trust the engineers knew what they were doing. Good reason to not use the mid grade.... at least around here the mid grade is ethanol mix. Is that stuff any good for our cars?

Up to 10% ethanol is okay in an SVX. (Guess I got that from the owner's manual.) No methanol.

Labeling a fuel "premium" doesn't make it superior to regular. Premium doesn't enhance engine performance by any measure; it simply has a higher octane rating. The higher the octane, the less likelihood of pre-ignition knock.

dcb

AlcyoneDaze · #47 10-18-2007, 01:04 PM

how many times can the same thing be said in a different way?

true1: the owners manual specifies 91 grade
true2: WORKING knock sensors will compensate for lower grades
true3: your performance will suffer
true4: octane rating measures only knock/pre-ignition resistance*
true5: our car has a high compression engine
true6: racing gas or 100+ octane serves no purpose unless car is modded
true7: 91 costs about $3 more over regular on a $45 fill-up

what else needs to be said? its a preferance/performance issue!
dancing tater tot for effect:

aaaaand.... DONE!

*and possibly more/better detergents

lhopp77 · #48 10-19-2007, 09:20 AM

Quote:

Originally Posted by AlcyoneDaze

how many times can the same thing be said in a different way?

true1: the owners manual specifies 91 grade
true2: WORKING knock sensors will compensate for lower grades
true3: your performance will suffer
true4: octane rating measures only knock/pre-ignition resistance*
true5: our car has a high compression engine
true6: racing gas or 100+ octane serves no purpose unless car is modded
true7: 91 costs about $3 more over regular on a $45 fill-up

what else needs to be said? its a preferance/performance issue!
dancing tater tot for effect:

aaaaand.... DONE!

*and possibly more/better detergents

Yes, it is a preference issue--the performance part has not been proven at all.

Lee

sicksubie · #49 10-19-2007, 04:52 PM

Quote:

Originally Posted by dcarrb

Up to 10% ethanol is okay in an SVX. (Guess I got that from the owner's manual.) No methanol.
dcb

Hmmmmm..... Methanol should not be used in a stock set up, but in a FI situation methanol is a viable option to cool the intake charge.

nextse7en · #50 10-19-2007, 05:37 PM

Quote:

Originally Posted by lhopp77

Yes, it is a preference issue--the performance part has not been proven at all.

Lee

Is this actually accurate?

High Compression SVX engine = knock prone
High octane gas equals = less knock
low octane gas in high compression engine = knock
The more knock, the more the ECU retards the ignition.
The more the ignition is retarded, the lower the efficiency of the engine.
lower efficiency = lower MPG, and lower peak HP and Torque levels.

I'd say that this issue has been proven, over and over and over again. There isn't a way to escape the logic. If you run regular gasoline in a high compression engine, you have to retard the timing from optimal. Thats why the owners manual specifies premium fuel.

They didn't tell you to put premium in the tank because they think it sounded like a good idea, they did it because they designed the engine to operate on it.

You probably won't hurt your car by putting regular in it, but you are absolutely, unquestionably diminishing your performance, and mileage.

I'll make an open bet with anyone on the board. $200 says that the exact same SVX will read more fuel consumed, and a lower horsepower rating on the dyno when running regular.

It may feel good to save that 3 bucks at the pump initially. But you are putting more gas in.

-Patrick

svxual · #51 10-20-2007, 06:25 AM

yep i agree wth u nextse7en. one of my staff got a 03 bmw and he thought i was nuts using 98 at 15cents litre dearer but he now uses it aswell he reckons its saves him bout $30 a week he drives bout 1500km aweek like me

svxual · #52 10-20-2007, 06:37 AM

and if u want2 get a bit more up'n'go i add a ltr of toluene b4 i fill up
hehe who needs Nos, and u cant smell it , i use it in my streetstock its like steroids 4 ur car

PDSides · #53 10-20-2007, 08:10 AM

Few herein are old enough to remember the days when we had only one grade of gasoline. Those old low compression ratio engines would run on even the poorest gasoline formulations. Then along came "high compression" engines for the masses. These engines required Ethyl gasoline, a lead-based compound that kept engine valves from burning. I've never known anybody getting ill from the effects of running Ethyl gasoline in their engines, although I'm sure all those oxides of lead released into the atmosphere didn't bode well for the environment. In the past few years I've seen a new trend - instead of the auto industry dictating fuel types, the fuel industry is beginning to dictate engine types. Maybe we need to take a look at energy sources, then develop engines to utilize those fuels, instead of the other way around. No, that won't work -- it makes too much sense!
Preston

Landshark · #54 10-20-2007, 08:50 AM

Quote:

Originally Posted by nextse7en

Is this actually accurate?

High Compression SVX engine = knock prone
High octane gas equals = less knock
low octane gas in high compression engine = knock
The more knock, the more the ECU retards the ignition.
The more the ignition is retarded, the lower the efficiency of the engine.
lower efficiency = lower MPG, and lower peak HP and Torque levels.

I'd say that this issue has been proven, over and over and over again. There isn't a way to escape the logic. If you run regular gasoline in a high compression engine, you have to retard the timing from optimal. Thats why the owners manual specifies premium fuel.

They didn't tell you to put premium in the tank because they think it sounded like a good idea, they did it because they designed the engine to operate on it.

You probably won't hurt your car by putting regular in it, but you are absolutely, unquestionably diminishing your performance, and mileage.

I'll make an open bet with anyone on the board. $200 says that the exact same SVX will read more fuel consumed, and a lower horsepower rating on the dyno when running regular.

It may feel good to save that 3 bucks at the pump initially. But you are putting more gas in.

-Patrick

12345

if it could run completely fine on 87, Subaru surely would advertise as such. they make sure to point out that the new Tribeca runs on 87 now. the owners manual states that (at least in my other Subes, probably also for the SVX) 87 can be used in a pinch, but "for optimum engine performance and reliability, it is recommended that you use premium gasoline".

Evil One · #55 10-20-2007, 04:10 PM

On a side note...
I drive my car hard... if I put it on the interstate, set the cruise @ 65, and drove it like I was competing for a fuel economy marathon... then it may not matter a whole lot about fuel grade.
The SVX has power, so says the green light on the dash, and it is LOTS of fun to use it.

Jim

crazyhorse · #56 10-20-2007, 07:59 PM

After being one of the "grade doesn't matter" guys I'll tell you that it does! While running 89oct I was passed by a mildly modded SENTRA. (hangs head in shame) Yes a lowly 4dr got by me, and he was on the PHONE, oh the shame of it all.
No more cheap gas for me.

Does it matter that the Sentra is turbo'd?

Crazy_pilot · #57 10-20-2007, 08:21 PM

Quote:

Originally Posted by shelfy

+1 for teh forester 2.5xt. i'm in the same boat not being able to get the smallest of things from home depot.

Ford Taurus wagon FTW!!!

porschekiller · #58 10-20-2007, 09:21 PM

toyota corrolla wagon!

Quote:

Originally Posted by Crazy_pilot

Ford Taurus wagon FTW!!!

SVX JAZZ · #59 11-11-2007, 02:43 PM

I have a 62 mile (round trip) commute each day and I set the cruise control around 67 MPH. I used to drive about 10 MPH faster but I have noticed some difference driving a little slower. I haven't calculated the difference but I do seem to get more miles between fill-ups.

My wife's car (Volvo with a T-5) is more forgiving with grades of fuel. We've run 87 in it for a while with no big loss in mileage.

Hondasucks · #60 11-11-2007, 11:44 PM

Quote:

Originally Posted by shelfy

+1 for teh forester 2.5xt. i'm in the same boat not being able to get the smallest of things from home depot.

That's what my 87 GL Turbowagon is for!

Quote:

Originally Posted by Evil One

Thats $6.31 a gallon... or $113.63 to fill an 18 gallon tank.
The cost of gas in other countries keeps me from complaining about my having to pay $2.75 a gallon for premium.

Jim

Damn, last gas I got was $3.39

for Chevron..

I discovered I get about 1MPG better on Chevron premium than Arco premium.. I think my next tank I'm going to try Plus and see if my mileage goes down.