One of the most asked questions on this and other forms is about fuel. Some have said the more oil content the better which is not true and this link will tell you why as well as other very good information. All so look on the left for links to other very good information.

http://www.*********.org/understanding_fuel.htm

Or better yet. Understanding Nitro Fuel

Droplets of water inside a fuel jug will contaminate the fuel. But there are ways to combat moisture.
Model engine "glow" fuel is made up of three key elements: methanol, oil and nitro methane. Many fuel manufacturers include other additives that are designed to solve any number of common problems that may occur with our fuel. But for now, let's only address the most common elements of the fuel and how you can care for your fuel to keep it fresh and stop it from going "bad." These steps will ultimately make your model engine operations easier.

Why would fuel go "bad"?
The largest portion of the fuel is methanol (alcohol). Methanol is hygroscopic; it attracts moisture. This can cause your fuel to be contaminated with water, which will cause poor engine performance. Additionally, the UV rays in sunlight will eventually break down the nitro methane if the fuel jug is stored in sunlight for long periods of time.

How can you tell when your fuel has gone "bad"?
The first indications will generally be the inability to start the engines at previously run needle-valve settings. Another clue might be that the engine has very poor idle, runs but bogs down tremendously during run up and/or will not attain the same RPMs you are used to.

How do I keep my fuel fresh?
If you have the opportunity, look for someone at a flying field on a sunny day who has a jug of fuel that is only ¼ full. What you may notice is that there are droplets attached to the top and sides of the fuel. This is the moisture in the air that is condensing inside the jug because of the greenhouse effect of the semi-translucent plastic jug. One way to overcome the greenhouse effect is to store your fuel in a metal can.


You can also combat the effects of the moisture in the air by squeezing all the extra air from your fuel container at the end of the day or transferring your fuel into smaller containers as the level of the fuel is reduced in your gallon jug. Many pilots will invest in half-gallon or quart-size containers and only bring that amount of fuel to the field on any given day. This allows their main supply of fuel to stay at home in a controlled storage environment, virtually insuring problem-free fuel.




Additional Fuel Information

If you read the R/C car magazines, engine instruction manuals or talk to local racers, you'll likely find conflicting information about car fuels. The main controversy seems to focus on how much and what type of oil is needed for a car fuel.

Here the straight scoop based on over 15 years of experience that includes working closely with engine manufactures, industry experts, top-level racers and the results of testing literally hundreds of formulas in all types of car engines and conditions.

Why Not Airplane Fuel

Car engines operate in a totally different environment than do airplane engines. Airplane engines spend a great deal of their running life at full rpm, they have a constant airflow from the prop to aid in cooling and instant throttle response and acceleration is not as critical as with a car engine.

Car engines spend most of their life accelerating from one corner to the next and are seldom at full RPM for more than a few seconds. They rely on an oversize heat sink head to dissipate combustion heat and racers actually tune car engines based on throttle response.

Fuel designed for airplanes typically have from 15 to 20% oil. While the manufactures that truly understand the requirements of car engines typically put 8 to 12% oil in their car fuel.

Why 8% to 12% Oil

Using high oil content fuels (above 15%) in gas car engines won't provide improved engine life, as some would expect. Through extensive testing we've discovered the point of diminishing return as far as oil content to engine life is actually around 8% for most car engines. In other words any more oil than 8% in the fuel does noting to improve the life of a car engine. In fact the secondary effects of high oil content fuels can actually cause engine damage by encouraging over lean runs. Here's how.

Using high oil content fuel causes a car engine to be unresponsive during acceleration acting as if the engine were running rich. Typically when using high oil content fuel, in order to get crisp acceleration and response, an engine will need to be adjusted overly lean. In addition the high oil content prevents lean bog when an engine is over-leaned thus allowing the engine to run at this lean setting without the customary telltale lean bog warning letting you know the engine is overheating.

In summary, high oil content fuels don't give added protection. The point of diminishing return from a protection standpoint in a gas car application is about 8% oil depending on the oil type and engine. Anymore oil than this doesn't offer added protection and has potential secondary effects that reduce performance and can actually cause you to over lean your engine in an attempt to get crisp throttle response and acceleration. Do yourself a favor and follow these two rules:

Rule #1- Always use a high quality fresh fuel designed specifically for gas car use that has between 8% and 12% oil preferably with at least some castor in it. (We recommend Blue Thunder Sport or Race Formula)

Rule #2 - Don't use airplane fuels or any other type of fuels that have over 15% oil in your gas car engine.

Nice cut and past job. I did not do this to keep from taking up so much room. That is why I posted the link and that way people can save it to there favorites with out all the extra. No harm done.

I can only speak from my own personal experience but I have found that the oil-rich synthetic/castor blended fuels like Traxxas Top Fuel do infact provide more engine longetivity (at least in my cars & trucks).

hmmmm, umm, yeh, well anyway, i have a guy that makes my fuel, and if you can tune it any good then you should be fine on 8, yes 8% oil and up to 30% nitro, its the tuning not a lot of oil u need. i HATE hobby shop fuel and will never go back ever again.

Dann

more oil means more lubrication for engine, meaning less wear, but less power, less oil means good power, which means not as much lubrication which means more wear on the engine

Using high oil content fuels (above 15%) in gas car engines won't provide improved engine life, as some would expect. Through extensive testing we've discovered the point of diminishing return as far as oil content to engine life is actually around 8% for most car engines. In other words any more oil than 8% in the fuel does noting to improve the life of a car engine. In fact the secondary effects of high oil content fuels can actually cause engine damage by encouraging over lean runs. Here's how.

Using high oil content fuel causes a car engine to be unresponsive during acceleration acting as if the engine were running rich. Typically when using high oil content fuel, in order to get crisp acceleration and response, an engine will need to be adjusted overly lean. In addition the high oil content prevents lean bog when an engine is over-leaned thus allowing the engine to run at this lean setting without the customary telltale lean bog warning letting you know the engine is overheating.

There is one thing I found faulty about that article and that was there recommendation to use bluethunder fuel. I had used that in the past and will NEVER go back to them. That is the only fuel that led me to burning down motors. Ever since I switched from them, I have not had any problems yet.

I cannot say anything about Blue Thunder as I have never used it put I have had problems with other fuels and know I will not use them. I understand where you are coming from as some like fuels I do not. I did not post this trying to recommend any particular fuel just thought it has some very good information. If I had been the one to cut and pasted the article I would have probably deleted the part about Blue Thunder. May I ask what problems you had with it?

I have all so found a lot of brands but not all have different blends and some of the blends are not as good as others do to the fact they have more oil content. The ones that have different blends normally classified them in 3 blends. 1 Sports or Bashing blend (high oil content around 16%) 2 Race blend (medium oil content around 12%) and 3 Pro blend (with the lowest content around 10%) I do not ever recommend running the Sports or Bashing blend unless you just cannot tune a engine.

i've always ran 16% or 10% nitro fuel in my trx.pro 15, the oil content is usually high and i have no problems whatso ever

LOL yeah ok suuuuuuuuuuuuuuure....thats total BS on Airplane engines they don't bog and instant throttle response is crucial on a plane...and nobody flies a plane at WOT constantly...so whoever wrote that has never flown a plane......also the prop don't really do squat for cooling....the engines located behind a portion of the prop which throws minimal air....and most planes run cowls and then no air off the prop hits it...props toss air at the outside edges not the inside where the engines located....thats why planes run higher oil content is to keep them cool.....heli's and ducted fan planes run almost the exact same fuel as a car engine.....but either way NO flier wants a plane that doesn't have instant throttle response and no flier flies at WOT constantly...plane engines are more critical than cars since planes aren't always on the ground.

Also Wildcat airplane fuel is 16% oil the car fuel is 14% oil.....go figure

What ever floats your boat. Airplane engines are what half the RPM or less!

Not half...ducted fan's run at same RPM's as most cars heli's also and just cause they list a RPM doesn't mean you've ever hit it....smaller props and so on increase RPM on planes.. airplanes aren't on the ground either.....toss your RC Car 200+ foot up in the air and see how well it lands That article's got alot of wrong information in it....If the article's correct why does OS recommend 18% oil in all their engines? Run 8% oil and see how they warranty it.

I sure see a look of plains hit the ground and never fly again. I have run Wild Cat car truck fuel and it was the worst I ever ran. But like I said what ever floats your boast or flies your plane. O I mean fly’s your plane. [sm=spinnyeyes.gif]

Perhaps your tuning skills suck or you read too many worthless and incorrect articles.

And we know which word in your statement fits you. What ever

everybody's gotta argue.

seems that way, yeh control line planes do run at WOT a whole run.... and there is a lot more cooling on most planes ive seen than a car, -body at 50kph VS no body at 150kph, the plane definatley gets more cooling.

Dann

best fuel i have ran in a truck is trinity for winter srping bashing and traxxas for the summer because for some reason it keeps the engine pretty cool but you still get power. airplane fuel doesnt have alot of oil content, oil is mostly used to cool down the engine. so yea....im into planes and i've noticed a difference in a planes glow plug after a bout a gallong of fuel and a cars glow plug. the cars is like clean where the airplanes is black. and note planes dont use air filters

46u LONG TIME NO SEE BRO lol, idk if u even rember me dont wory about badz he always seams to start fights on this forum. i havnt read the link on the fuel. but this is funny ok i just finished a gallon about 2 days ago and it was from last winter its spring now. the gas sucked but it still ran it was kinda wired but hey it worked then i striped my servo[:@] got a new one and finshied the last few drops and now im onto a gallon of traxxas top fuel to try it out this is my 3rd gallon lol well 46u nice seeing you but im going to go airbrush some more peace out guys

I know what you mean about you know who! I see he has not changed any! I just finished off a gallon of fuel I had since last June and it was just fine. I keep my fuel in a climate control dark area and I all ways squeeze the bottle to get as much of the air out that I can. Let me know how you like the Traxxas top fuel. I have a real big problem going on. The only poor excuses for a hobby hope we had anywhere near to me is going out of business and it is no wonder as there service has never been very good! The only thing I use to get from them is fuel. Now I cannot find it unless I want to drive about 100 miles to get it. I have found some places about 60 miles away but they do not carry any Race blend other then 30%. I am going to try and find people around here with the same problem and see if they want to go in on a case from Tower Hobbies. I have not been around for a while do to heath and finances, which is not getting much better. O well one day at a time. Good to hear from you!

im doing the 2nd part of this post.i kinda group gas that way to. but its a little different. i dont burn thre alot of gas i drive sometimes for fun but i try to conserve gas. well moving to oregon i do it like this

(higher oil (12%+) -summer-fall, winter i go for a brand like around 10% and spring if im still on winters gas when its gone i get around 12% and use it into summer i do it by the seasons im not a hardcore racer im actually into this hobby cause i love to work with my hands on anything with a motor. i spend half my time working on my truck and half my time actually driving it. i enjoy closeing my door, puting on the radio, and just reset it up or, rebuild this, or oil that its calming to me. then when i go outside i dont bash it as much as drift it in the dirt i did a long drift around my truck the other day i mean 10-15 feet sideways on the gas going fast, i enjoy this hobby cause i can do my own thing and learn 10 diffrent ways of doing something but, it makes me think of what way i have to do it for my self. its all about learning. if you want to run 3% oil and 30% nitro well go for it!!!! but u will learn that it will fry your motor. or if u run this with that it will do this ect... its a great hobby to learn guys. im glad i found the world of RC
thats my 10 cents a little off topic but i think acceptable

Exactly! My airplane engines run hotter than my car/buggy engines. If you have ever seen the heat sink on a plane, you will notice there is little area for any kind of cooling. Not to mention all my engines are behind cowls. I also have instant throttle response for tight aerobatics.

I can't even remember the amount of times I come in for a landing and just about 5 feet off the ground give it WOT and pull away before I land due to something I didn't like. Without throttle response I would have landed in an unexpected manner.

I love how they say it will increase chances of over lean runs.
An engine needs a certain amount of methanol to run. With more oil, there is less methanol, requiring a richer tune. With less oil there will be more methanol requiring a leaner tune.

I run boat and plane fuel in my car and it works great. I don't notice much of a difference in racing fuel. Tunning using high oil % is just as easy/effective.

Ryan

Exactly ryan_t888 you can't tell someone who ONLY runs RC Cars how planes operate....if they've flown or owned one they'd learn quick a sluggish engine means you take your plane home in a garbage bag...throttle response is much more important on a plane than any car....and planes don't cool via props as these car dudes believe...that article was written by someone clueless about airplanes. Here's a pic of my Sig 300xs...running a Saito 180 notice the 2 small cooling holes in the front of the cowl....Odd but most RC Cars have the entire front windows cut out not to mention the entire heads sticking out the car.....then again us plane guys are clueless That's why our plane engines last 10+ years

You guys are reading way too much into that article. The principals stated therein are sound. Airplane fuel is for Airplane engines, not for trucks. How many times do you drop to idle when your plane is up at 100 ft? Ever constantly blip the throttle for 20 seconds at a time? The way in which the engines are run are totally different between the two- I think we can all agree on that.

Did I misread something in previous posts? Did someone say something about wingers using the same fuel as cars/trucks? Because I cannot understand why you guys are going off about how the author knows nothing about planes. That article has nothing to do with how one should run an airplane engine.

And someone needs to bone up on his rc car knowledge. Where would you get the idea that an airplane engine has the same rpm as a car/truck engine??? My .12 will rev up to 42K, and the powerband starts at around the 20K level - about what an airplane engine max's out at. And there is a reason we HAVE to cut holes in our bodies and have big cooling heads: The trucks are not constantly moving at a good clip to ensure proper airflow and cooling. And badz, I guess all the semi-pro drivers I know all suck too, because none of their engines will last more than 10 or so gallons. Must be nice to be the only knowledgleable person in the whole world!

You wingers talk some good talk, but I see no emperical evidence to counter what is said in that article.