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93 octane worth my money?

12K views 51 replies 25 participants last post by  jmr 
#1 ·
so since its my brand new truck and all, i was thinking of spoiling it rotten with 93 octane gas every fill up. any pentastar mechanic super techs out there know if its a good idea? the manual says 87
 
#2 ·
87 will be best. Using higher octane than required is not only a waste of money but promotes carbon buildup and can actually decrease performance. You want to use the lowest octane possible without causing detonation/pinging.

Hopefully at some point a tuner will be available for that engine.
 
#7 ·
I used 93 octane in a car when I was younger thinking it was better, after about 6 months the engine would shudder and make a funny sound, like a metal on metal sound. I had it checked out and they weren't sure what was causing it, just for the hell of it that asked me what kind of gas I was using and I told them 93 octane and they said with confidence that's the problem, they called it ping.
 
#9 ·
Are you guys joking here???
On my Tacoma, that I just traded for the Ram, it Pinned with 87 Oct and rode so much stronger with 93! Used 93 most of time on it for 3 years, never had a problem, run stronger with it.... Only cost more....
How about all the claim that Shell has about their claims of Cleaner fuel, etc !!
So, is it just different with the Ram???
Your thoughts please!
 
#11 ·
I have friends who claim better fuel economy, more power, by using a higher octane fuel. Researching on the web, gasoline has 114,000 BTUs per U.S. gallon, 87-94 octane. Octane is a number assigned to a blend of fuel where it will not knock under compression. Knock or pinging is the fuel igniting under compression before being ignited by the sparkplug. So if your truck isn't knocking use the lowest octane number and save your money.
 
#12 ·
Even with a hemi and custom tuning, you won't gain much rwhp. From a custom econo 87 octane dyno tune to a custom 93 octane dyno tune, I only picked up 7 rwhp or so.
 
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#16 ·
Sorry, but I"m dissapointed with all of your answers. The octane ratingof gasolene tells you how muchthe fuel can be compressed before it spontaneously ignites.When gas ignites by compression rather than because of the spark plug, it causes knocking and pinging. Lower octane gas can handle the least amount of compression. The compression ratio of your engine determines the octane rating of the gas you should use. One way to increase the horsepower of an engine is to increase the compression ratio. So a high performance engine, Has A Higher Compression Ratio and Requires Higher Octane Fuel. I run 93 octane in my Hemi, and I"ll run any 345 HP Hemi Dodge on 87 octane any day. the guy that traided the Toyota for the Dodge, you were right! You ran the high octane and saw benefits in that truck. THINK ABOUT IT
 
#17 ·
Oha...
Ok.
First-the higher octane is not necessary if the motor layout is for lower octane.
Technically it also don't hurt. NO, THERE IS NO DAMAGE BECAUSE OF HIGHER OCTANE.
the octane number indicates the willingness to ignite by it self.
Low octane ignites by it self at a lower temp or pressure than high octane.
Therefore there is the knock sensor which signal is used for adjusting the ignition point.
The point is always knock border = point, where the gas mix ignites by it self uncontrolled.
All the system does is, with higher octane to move the ignition point later and there is higher compression pressure when the fuel ignites. The pressure increase is higher and so the force wich pushes the piston down.
That's all.
If you have a low pressure engine, it will not make a difference.
Btw-in highspeed-and rpm counties you wiss see a difference, because the effect increases with higher rpm.
In us with 55 mph and 1500rpm you can even drive a 97 octane engine on 87 octane because you'll never reach the region where it would hurt. My old bmw 540i is the best example with 250000 miles and all with 87 octane.
If u have soot, then from short distance or bad fuel quality from the cheapest gas station.
 
#18 ·
Not sure what the V-6 Powertech should run on. But Ma Mopar tells us Hemi guys that are pumpin ponies right in the owners manual to run 89 OR Better( hint hint ). And yes the ECM retards or advances the timing. Would you rather the engine change the timing so it ignites the fuel before the fuel blows on low compression? or run higher octane fuel to build higher compression which builds more power? In the V-6 you may be designed for low octane, but the Hemi should have the good stuff. I pay 20 cents more a gallon for 93 octane. thats $2 more on $40 worth of fuel. Thats the price of a 12 oz beer. listen to your mother Hemi owners
 
#20 ·
Low pressure engines have a low compression, running smoother and having more torque than high compressed engines.
Low compression is also safer.
High compressed engines running normally with higher rpm at max torque, having therefore higher hp but compared lower torque.
For a normal 2-valve engine you can say that the max torque without turbo is ~80% of the liter size. A 4-valve engine can have up to 100%.
These engines normally need higher octane because the pressure is higher and so the engine needs higher octane because the gas mix can self ignite at this pressure. This explains why a hemi needs higher octane then the 4.7l.
I try to explain it as understandable as possible. If I go deeper, it will get complicated. It explains it as good as possible for now. I hope.
 
#24 · (Edited)
Engine Octane values for an engine are based on the Compression ratio, the 4.7 has a Compression Ratio 9.8:1, this engine can run on 87 Octane, the 5.7 engine has a compression ration of 10.5:1, its recommended Octane is 89. but can also run 87 without knocking.

And Yes snrusnak is correct, 2 valves per cyl
 
#25 ·
Here's a little Octane Information for those who would like to do some reading.

Unless your engine is knocking, buying higher octane gasoline is a waste of money. Premium gas costs 15 to 20 cents per gallon more than regular. That can add up to $100 or more a year in extra costs. Studies indicate that altogether, drivers may be spending hundreds of millions of dollars each year for higher octane gas than they need.
It may seem like buying higher octane “premium” gas is like giving your car a treat, or boosting its performance. But take note: the recommended gasoline for most cars is regular octane. In fact, in most cases, using a higher octane gasoline than your owner's manual recommends offers absolutely no benefit. It won't make your car perform better, go faster, get better mileage, or run cleaner. Your best bet: listen to your owner's manual.
The only time you might need to switch to a higher octane level is if your car engine knocks when you use the recommended fuel. This happens to a small percentage of cars.
About Octane Ratings

What are octane ratings?

Octane ratings measure a gasoline's ability to resist engine knock — a rattling or pinging sound that results from premature ignition of the compressed fuel-air mixture in one or more cylinders. Most gas stations offer three octane grades: regular (usually 87 octane), mid-grade (usually 89 octane), and premium (usually 92 or 93). The ratings are posted on bright yellow stickers on each gas pump.

What's the right octane level for your car?


Check your owner's manual. Regular octane is recommended for most cars. However, some cars with high compression engines, like sports cars and certain luxury cars, need mid-grade or premium gasoline to prevent knocking.
How can you tell if you're using the right octane level? Listen to your car's engine. If it doesn't knock when you use the recommended octane, you're using the right grade of gasoline.

Will higher octane gasoline clean your engine better?


No, as a rule, high octane gasoline doesn’t outperform regular octane in preventing engine deposits from forming, in removing them, or in cleaning your car's engine. In fact, the U.S. Environmental Protection Agency requires that all octane grades of all brands of gasoline contain engine cleaning detergent additives to protect against the build-up of harmful levels of engine deposits during the expected life of your car.

Should you ever switch to a higher octane gasoline?


A few car engines may knock or ping even if you use the recommended octane. If this happens, try switching to the next highest octane grade. In many cases, switching to the mid-grade or premium-grade gasoline will eliminate the knock. If the knocking or pinging continues after one or two fill-ups, you may need a tune-up or some other repair. After that work is done, go back to the lowest octane grade at which your engine runs without knocking.

Will knocking harm my engine?


Occasional light knocking or pinging won't harm your engine, and doesn't mean you need a higher octane. But a heavy or persistent knock can lead to engine damage.

Is all "premium" or "regular" gasoline the same?


The octane rating of gas labeled "premium" or "regular" isn’t the same across the country. One state may require a minimum octane rating of 92 for all premium gasoline, while another may allow 90 octane to be called premium. To make sure you know what you're buying, check the octane rating on the yellow sticker on the gas pump.

Oh by the way: Higher octane fuels burn slower so unless you can increase your initial advance (tuner) you will not see any difference. Also when a vehicle is tuned to use lower octane fuel a higher octane will create carbon deposits and over time will cause engine ware, overheating, and poorer fuel economy. Today's ignitions are computer controlled many are distributor-less so we shade tree mechanics can't mess with them. Many of today's vehicles recommend 91 octane but can use 89 or 87 if you don't hot rod them or over load them. Food for thought.

and all this information is taken from "American Petroleum Institute website"

http://www.api.org/ <---------- lots of good reading

http://www.consumer.ftc.gov/articles...ctane-gasoline

http://www.examiner.com/article/does...-improve-mpg-s

http://mechanics.stackexchange.com/q...ve-gas-mileage

http://www.nicoclub.com/archives/gas...ane-myths.html

http://www.carsdirect.com/car-buying...s-fuel-mileage

http://www.wanderings.net/notebook/M...sWorthTheMoney

http://www.whatcouldbegreener.com/14...will-cost-you/
 
#28 ·
Lets remember the ethenal thats in the fuel. My trucks an 04. Thats pre ethenal. If you want Cheap gas, buy Cheap gas. But dont try to dispute reasons for us non Cheap guys to by good, productive fuel. And you dont need a tuner to run high octane. Its not race fuel. You have a truck that costs $30 to $50k and you probably speed on the highway but when it comes to fuel it has to be the cheapest. Thats like eating fast food daily to save money but your body suffers. Well do as you will. Mopar to ya. Good luck!
 
#29 ·
No, I'm absolutely not an engine guy...
Have no idea how that thing even works...
I will enjoy my mopar and for very long with the cheapest gas and oil I can find.

Btw- eating everyday in a five star restaurant is like spending twice as much for half of the food, thimk you done something good and the whallet suffers.
The truth, Lman, is in the middle. Safe where you can and spend where it makes sense.
The problem is to know, what is what.
 
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