Gas Octane

I kept seeing articles on mags that said high octane gas requires more compression to burn and is made for high performance engines. So if your engine doensn't have enough compression to burn it, the unburn gas will become deposit in your engine.

The question is what kind of compression does the Tacoma's engine have?

 

10:1

 

Now I forgot what is the minimum compression to run 93 or 89 ?

 

I was going through my owners manual the other day. I did notice where 87 is the minium octane but 91 is the reccomended minium.

(Don't know if this has already been posted)

 

I doubt it. Octane does not affect combustibility. It just affects flash point. 93 octane gas burns just like 87 octane. If there's gas left over after a combustion (which there really shouldn't be), it's more likely to do with the ECU pumping too much in there in the first place and not the octane rating.

If you run a higher octane than needed by your engine, you won't do much worse than just spend some extra money on fuel.

 

i used 93 for 2 tanks, just to see what happened, got worse mileage on teh highway...regular it is from now on....dont fallf or the hype, regular (87 in jersey) is just fine

 

just bought '10 doublecab prerunner and dealer told me to run 87,got 17.9 on first tank

 

Monrad and Chris4X4 i believe have answered the question at hand the best.

YES THERE IS A SIGNIFICANT DIFFERENCE BETWEEN THE GAS RATINGS

ALSO; there is a difference between gas brands. the "top tier" gas brand, ie... shell, mobile1, Cheveron and recently added to the list COSTCO. are brands that contain the base federal required addatives for lower emissions and less carbon build up on the internals of the motor, but they also contain their own blends and better quality addatives. that is why companies such as BMW, Mercedes, TOYOTA and Honda recommend and some times REQUIRE use of top tier brands.

HIGHER OCTANE RATINGS WILL PROVIDE BETTER PERFORMANCE, but only if paired with proper supporting specs in engine managment,,, ie spark plugs, timing, filters, air fuel mix. You can have the lowest rated gas on the market but tune your motor to put out more performance from that gas than a higher rating. or you can put Race Gas in and get crap performance because your motor is not tuned for that rating.

Performance is Air/Fuel mix based with a support stand of efficiency of burn.

get the proper managment and spark and you will get good performance from the gas you tune it to. 91 is a standard for higher performance when used in conjunction with higher air flow, lower back pressure exhausts or forced induction due to its COOLER SLOWER burn with less remaining gases. 91 is (when mixed properly with the right air volume) a lighter gas mixture, but when compressed and ignited it creates a more explosive energy.(if you have the right air flow and timing and spark) this creates more power and thus better performance.

as far as alternative addatives,,, Sea Foam is very popular and actually works very well. its corrosives are able to eat some carbon off the tops of valves, but the best performance is if you do a manifold feed and let it sit for a few minutes then rev the crap out of your motor to clear it out.
Turbo 108 is also a OKAY brand,,, not the best though
STP is crap!!!! so is Lucas, NOS, and all those other HONDA KID addatives.

the best addative on the market runs about $25 a can and is made by BG. its called 44K and is amazing. but expensive.

they also make oil addatives which can work wonders on viscocity and cleaning out some of the damaging sludge associated with ANY type of oil.


my advice..... run only 90-93 octane Standard unleaded gas from a top tier company,,, Cheveron, Shell, Costco.

Also, age of the gas station matters too. The older the station or its tanks, the more corrosion and rust or water will be in the tanks, i have filled my bike up at a very old cheveron before and it ran like crap. you will want to look at inspection certificates that should be on the pumps themselves and use your general comon sense... if the station looks a million years old and has a T-Rex pissing in the tank then you might not want to fill up there.

 

having a manual transmission i can tell the difference when i am running 89 as opposed to the 87. its alot smoother going into first from a dead stop with the 89. i also seem to get better mpg. still tracking my milage, ill chime in when i have enough miles driven with each( the 87 and 89) to give solid numbers.

 

I don't think any body is quesioning the difference in octane. The question is if the Tacoma engine meet the warrant to use high octane to gain any benefit.

 

no it doesn't, not in nj, not with my truck and not in real life, anyone can say what they want, but if you have to tune the engine to work with higher octane, then what everyone is asking is, "is higher octane better" then no it is not, not unless you wanna tune the engine, my protege ran fine on regular, but with a turbo, cai, fmi, blah balh, it needed the computer to tune the engine and use sunoco 93.

 

performance can be all aspects, from longevity of the valve train to the rings or even horsepower. when a motor needs to be tuned i am talking about high horsepower or high modification applications, normal driving conditions and bolt on low mod apps such asexhausts and intakes. your motor will be provided the ability to perform better with the better quality fuels, and in MOST cases higher octane. put it like this,,,, will a vehicle performe better at an elevation in California or in Colorado???? the factor that comes into play is the amount of AIR available. now factor that same effect in with the combustion qualities of the different octanes and you get basically the same effects. NOT ALWAYS, BUT MOST OF THE TIME.

to be plain,,,,,, higher octane and TOP TIER better quality fuels are not only recommended in the vast majority of today's high performance vehicle, but also are better for your motor and RESEARCH HAS SHOWN better for the enviroment too.
with gas prices and fuel milage coming out about equal between the 3 choices,,, why not just run the good stuff and feel better that your treating your vehicle the best you can???? but if you really want proof..... take your vehicle to a dyno, put new plugs in with a tank of each grade fuel and see what happens.

 

P.S. my girlfirnd put 87 in my 2000 manual tranny one time, it ran like crap and i got about 125 miles less to the tank as i regularly get. i pulled the plugs and even though i had just replaced them about 2 months earlier 2 of them were fouled out. replaced the plugs with new ones, added a can of

$25 BG 44K Fuel System Cleaner Power Enhancer 11oz.

BG 44K to a fresh tank of Shell 91 and went back to getting almost 300 miles to the tank.... to me the proof is in the pudding. but hell, what do car manufacturers like BMW know right..

 

Toyota isn't doing their spec with 91 Octane. The number on the pump is the R+M/2 method. Essentially Toyota is saying 87 octane is the gas to run, the 91 RON number is already built into the 87 number on the pump. Toyota is not saying to use 91 Octane measured by the (R+M)/2 method, that would be entirely different. See this link for explanation of octane measurement.
http://www.nsxprime.com/FAQ/Miscellaneous/FuelAdditives.htm

under "What does High octane mean?

 

very nice, i was looking for that same type of research web page to post.

by high octane i THINK ppl are mostly talking about what is readily available at the typical gas station.... 86 or 87, 88 or 89 and 90 or 91 (with the few exceptions of the area that has 93)

to me when i am speaking of high octane i am refering to the premium or super unleaded. typically the little button saying 90 or 91 for those simpler and visually memory ppl. lol

now i did once put about a 1/4 tank of VP 110 mixed with 3/4 tank of shell 91 in my truck to clean it out, got horrible gas milage but the performance was amazing. it did run better after that though

 

Perhaps we're just lucky here in Ohio. I use 93 octane from Shell. --good stuff! ----engine happy!!

 

yeah i wish more places around here in New Mexico had 93. i usually through in a sea foam or a smaller can of turbo 108 about every month, kepps my baby purring real nicely. i try to only use Shell 91 or in the places where i can get 93 i use that.

here is my opinion from a high performance motorcycle builder/tuner and high performance sports car builder/tuner

if you have a fuel injected vehicle use higher octane... it will mix better and you will get all around better performance. if you have carbs.... well it all depends on how you set them.... i put a set of side drafts on my buddies gen1 RX7 and he only would use mid grade, and we actually tuned it better on that than on premium. So really like i was saying before...... it all depends on the type of motor, mods and the way it is controlled (plug type and fuel spray type,,, EFI or carbs)

But really you cant tell unless you put the same vehicles through the same exact controlled tests with the same throttle responses, oil types, tire type and inflation, road type, elevation, air temperature, wind resistance......
EVERYTHING COMES INTO PLAY WHEN YOU TRY TO GO OFF OF GAS MILAGE. i can get 50 mile less to the tank just because it is hot out or there is a head wind or i decide to have a heavier foot that day. or i can get amazing milage because i pussy foot it and i have a tail wind...... NO, FARTTING OUT THE BACK WINDOW IS NOT CONCIDERED TAIL WIND.

Best advice.... use one type, then another, then another and see what you think your motor seems happiest with.

 

Will I see any difference from 87- to - 91 in my 6cyl TRD??