Say your engine runs on 87 octane, will it ever hurt the engine to put 89 or even 93 octane in, and if it doesn't, does it make the engine run any different performance or sound wise?

 

Octane is the rating at which detonation occurs or in this case doesn't. A higher octane will cause less detonation. Your engine will not see any benefit of higher octane as far as performance unless 87octane is causing your vehicle to ping or pre-detonate. Many cars have this problem and people never realize it. Higher octane will burn hotter and cleaner so your cylinders and valves will remain a bit cleaner. i always run mid grade to be safe. Detonation is an engines worst nightmare!

 

Alright so it shouldn't cause any malfunctioning or any problems if I were to put mid or high grade octane in the gas tank?

 

Id say watch the 89, (mid grade). Here in ND ALL 89 is ethanol enriched and i lose milage with it. Only time i run 91 is on a long road trip as its the only time i see any benefit using it, (increased milage).

 

its fine. i switch every now and then from 87 to 93. now that i have the superchips programmer i use 93 oct for the performance 91 setting, but will eventually switch to the 87 setting when it starts snowing as i wont need the performance setting in snow.....

 

89 octane also has the additives that the premiums have. They do a good job at keeping the engine and fuel injectors a little cleaner than 87 would. Performance will be slightly better but not that noticeable; however, I have noticed that with 89 or 93 the truck runs a bit smoother and quiter. Mileage is pretty similar across the board, but since gas is so cheap now I like to run higher octanes. I usually stick with shell or mobil stations as well. Avoid discount gas stations like clark or thorntons.

 

Additives depend on where you buy your gas...not the octane rating. Shell only has detergents in their premium gas (v-power) where chevron has detergents in all 3 octanes(techron). Then there's the gas stations that are usually 10+ cents cheaper than a top-tier gas station...they charge you to use your ATM card (at least Arco does) and they don't have detergents. Sneaky bastards..

 

Yeah you got to watch where you go. I like to rund shell V-Power (93) octane in my ram. I know its not necessary, but like I said it runs smoother and performs a little better. Which stations does chevron have now. Is it chevron and marathon? BP puts invigorate in their premium as well. Anyways even if you run a lower octane just run a fuel injector cleaner through when you do your oil change. basically ends up in the same place in the end.

 

You can have half a tank of 87octane and pump the other half of 93 octane and no issue's will arise. Mixing different octanes ofgasoline is not anything to worry about if your vehicle only needs the minimum 87 octane to function properly. Gas doesn't work the same as engine oil. You cannot mix different grades of oil. They don't mix. They remain separated the entire time they are in the engine!

 

the higher octane gas from the better stations like shell does give a noticible amount of performance especially when used with other mods like CAI, and/or thermostat. MPG will go up a little too because of the small increase in HP.

ive done the real world test on the RAM by running 3 gals of 87 and then 3 gals of 93. i got the gas in 2 separate fuel containers and ran the RAM til the fuel light came on and then filled it first with the 87 then ran it till the light came on and then filled the 3 gals of 93. the fuel was from a shell station.

i ran 5 identical tests of each octane. these 2 sets of tests were all within 2 hours of each other and in the afternoon when the ambient temp was stable. the truck was allowed to warm up before the first set. then after the fifth run allowed to cool for an hour and then before the start of the next set of runs was warmed back. the gain is attributed by the facts below.

with the 87 octane, simply floored it and held the throttle to the floor. no tire spin and noticable bogging off the line with sluggish 0-60 runs. then 5 gals of 93. same as first set floored and held. considerable tire spin and no bogging off the line with quicker 0-60 runs. these runs were not on the exact same spot on the road but within 20 feet of each other.

i have done the same thing however with the rubicon and did not notice the difference that i have with the RAM.

being that i have no concrete data for the 0-60 times just a feel. i am getting a gtech performance meter for xmas and plan on doing the same type of runs with it to get a better feel of the difference between 87 and 93 octane fuel since there are many that feel that there is no difference in performance between the 2 octane fuels.

i await the flames...