Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
I drive a 1995 Camaro Z28. The owners maual says to use minimum octane of 91. So I ahve alawys used premium. I used to be only a little bit more expensive, but now, I am looking at as much as 30 cents a gallon more...
Where do you live that premium is 30 cents a gallon more than mid-grade? And why the hell is it so much more expensive?
Quote:
Originally Posted by hoffdano
30 cents a gallon X 15 gallons = $4.50 per fill up
If you filled up every week that's an annual difference of $234.
If the vehicles loses 5% of its hp, but the driver doesn't need the power, then using lower octane fuel simply saves a meaningful amount of money. That assumes the engine runs well otherwise.
Does your calculation also take into account the loss of fuel economy?
Personally, I don't trust any pre-OBDII car to adequately retard the timing to accommodate a lower-than-recommended octane level.
Where do you live that premium is 30 cents a gallon more than mid-grade? And why the hell is it so much more expensive?
Does your calculation also take into account the loss of fuel economy?
Personally, I don't trust any pre-OBDII car to adequately retard the timing to accommodate a lower-than-recommended octane level.
That was a point I made in an earlier post. Your economy will drop off with a lower octane fuel. Try the lower octane and see what your fuel economy is over several tanks of gas. Compare it to what you are getting now. You may in the long run save more money using the higher octane fuel. I have an FJ Cruiser and I save more money by using the higher octane fuel.
My Vette had an LT-1 engine. I had 350 CI with 370 horses. I could not run anything but High Test or 91-93 Octane. Otherwise 89 octane would make the car sound like a tin of nuts and bolts.
Probably the fastest car I ever owned. My race car friend owned a Cobra and he did beat me fair and square while his car was overheating mine was just getting warm.....
That was a point I made in an earlier post. Your economy will drop off with a lower octane fuel. Try the lower octane and see what your fuel economy is over several tanks of gas. Compare it to what you are getting now. You may in the long run save more money using the higher octane fuel. I have an FJ Cruiser and I save more money by using the higher octane fuel.
HHUUMM How did you get away with a low octane fuel in an FJ Cruiser? My co-worker has one and it too could not run with 87, 89 octane.
If you use gas with an octane rating lower than recomended, the engine will retard the timing to prevent engine detonation. Basically, the car will make less horsepower and get worse gas mileage.
Think of it like this. If you have a 250 hp car that requires premium fuel (91-93 octane) and get 25 mpg, if you use 87 or 89 octane fuel, you will get 240 hp and 22 mpg.
Many people think they are saving money by using a lower octane fuel, but the reality is, if gas is $3 a gallon for 87, you pay ~20¢ for premium, or ~6% more per gallon, but get on average ~5% more engine power and ~10% better gas mileage. On cost per gallon of gas and mpg alone, you come out ahead using the higher octane fuel, and the added engine power is a bonus.
If you have a 10 gallon tank, that would be 250 miles per tank for $32 with premium, or 220 miles per tank for $30 with regular. That 30 mile per tank difference equals $3 using regular versus the $2 it would have cost you to just buy the premium.
The caveat is using an octane higher than what is recommended by your manufacturer will not increase engine power unless you have one of a select few GM 2008 vehicles.
The net is, lower octane gas equals lower mpg, and you end up stopping for more gas with the lower octane, plus there's the power hit, so it costs you more money to run the lower octane fuel.
Toyota sent out a release to it's dealers stating that it's ok to use lower octane fuel in the FJ. The release went on to say that the HP and fuel economy testing that was done was with premium fuel. If you use a lower octane fuel fuel economy and HP numbers will be lower.
I never used 87 in my truck, but I did try 89. Fuel economy decreased by a few miles per gallon and I ended up saving by using the premium.
I had a '94 Impala with the LT1 engine. I always ran 87 octane, because I am a cheapskate, and I never had any issues with it. If you try it, just keep a ear out for any spark knock, and watch the temp gauge.
Well, the Impala LT1 has iron heads and runs lower compression, so the missing 25ish ponies compared to an F-body LT1 allow you to get away with running cheap gas.
Coming just in time to give the Impala SS some bite to back up its bark was a heavily revised 5.7-liter V-8 carrying the honored LT1 label. Running on lower compression that allowed it to get by on regular gas, it produced 260 horsepower in this application, versus 275 in the Camaro Z28 and 300 in the Corvette -- both of which required premium. Nevertheless, it represented an 80-horsepower increase over the previous 5.7-liter V-8 offered in Chevy's full-size line.
Also new was a 4.3-liter V-8 producing 200 horsepower, which was the standard engine in Caprice sedans and wagons. While the Impala SS came standard with the 5.7-liter LT1, that engine was also optional on Caprices. Regardless of engine, the only transmission offered was a four-speed automatic.
I agree. Except for the V6 part.. My supercharged 3.8 buick lives off of premium
Well...so does my turbocharged 3.8 Buick. In fact ANY forced induction car should be ran on premium. Turbo and s/c'd engines are even more prone to detonation and have very little tolerance for it.
I only said "V6" because the little 3.4 (and later 3.8) V6's I don't believe need anything other than 87.
Where do you live that premium is 30 cents a gallon more than mid-grade? And why the hell is it so much more expensive?
Does your calculation also take into account the loss of fuel economy?
Bout time someone said it.
In calculating my freeway mileage on both cheap and premium fuels, I got SIGNIFICANTLY better mileage on premium. Usually between 50 and 80 more miles per tank.
Well...so does my turbocharged 3.8 Buick. In fact ANY forced induction car should be ran on premium. Turbo and s/c'd engines are even more prone to detonation and have very little tolerance for it.
I only said "V6" because the little 3.4 (and later 3.8) V6's I don't believe need anything other than 87.
I agree 100%. BTW, wanna trade my S/C 3.8 car for your Turbo? haha.
Please register to post and access all features of our very popular forum. It is free and quick. Over $68,000 in prizes has already been given out to active posters on our forum. Additional giveaways are planned.
Detailed information about all U.S. cities, counties, and zip codes on our site: City-data.com.
Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
In fact ANY forced induction car should be ran on premium. Turbo and s/c'd engines are even more prone to detonation and have very little tolerance for it. 
