I have an app in my phone that leads me to the cheapest gas closest to me....of course i get grade 87 for my stock 400m
But i was thinking if my engine would run better if i started to buy the "better" gas from chevron?
Would it run better? Does it really clean my fuel system when running through?
And would you guys recommend me running on a higher type of grade?
Or does it really not matter and all this stuff is boloney?
Like i said, i have a bone stock 400m with no smog stuff...i do however plan to get a couple of bolt on parts in the near future

 

My truck seems to run better when I put a higher octane gas in it, maybe I am just imagining things though lol

 

May i ask what grade do you put in your truck? And what size engine?
Thanks for the quick reply

 

Sometimes I run regular 87 octane and everyonce in awhile, I will run 93 octane.

 

The only thing octane rating has to do with is the degree to which the fuel can be compressed before it self-ignites. That's why high-octane fuel is specified for high-compression engines. You do not need to run high-octane fuel in any of these trucks as they came from the factory. Increased octane rating is completely transparent in a stock motor.

If you think your truck "runs better" (which is a qualitative term) on high octane fuel, it's purely a psychological effect due to having spent more money on gas. It's the same reasoning behind the fact that people often think food tastes better when bought at a fancy grocery store vs. Safeway. Sorry guys but it's in your head. No one on this forum has ever provided scientific evidence to prove otherwise.

 

Do I get any advantages using chevron gasoline?

 

Gasoline is a fungible product, in other words it just meets a certain spec. Depending on your location your Chevron gas my come from a Shell refinery. The only difference will be the minute amount of additive put in at the rack when it's loaded on the truck. And we are talking a small percentage, like less than half a percent. Octane as stated above is jsut the resistance to knock, and at the pump all that 87 rating means is that it is the minimum. Most 87 fuel will have a higher than 87 rating if tested.

 

Maybe because the couple times I did run a high octane gas was because i had a bottle of carb/injector cleaner in the tank. Probably was the cleaner that made the truck run better, not the gas.

 

Well, if the US military only test their vehicles with Chevron, 76 and Shell that should tell you something. It has been proven the above three brands are a bit better than the rest with Chevron being the best. As far as octane, fmc400 nailed it.

 

i work at one of the box parts stores. i do many many code checks every week. i have come to the realization that at least the locally Chevron gas may use a bit more than 10% Ethanol.

We have a recurring problem with the "Evaporative Emissions" codes whenever the outside temperature rises rapidly. We have come to realize, and been backed recently by news reports, that Ethanol seems to vaporize at lower temperatures than regular fuel. Here in N AL at times we may see well over half of our complaint customers come from...Chevron customers. i think that the local distributor may be adding even more Ethanol than what the industry standards may be.

Now, what does this have to do with mid 70s Fords? Well Ethanol can break lose tons of shellack in carbs and gas tanks. It can cause a bunch of problems if your truck has not been using Ethanol or is prone to sitting for periods of time.

For me, reality check time, Ethanol, for better or worse, is the most available gas nationwide. By using Ethanol gases my tank, carb, etc stay relatively clean and shellack free. You cannot depend on finding 100% Pure Gas when travelling and my dent does travel some. i use better 10% Ethanol Gas myself. That means gas from: BP, Texaco, Shell, Exxon, or Murphy's @ Wal-mart. From a bunch of experience i rarely see complaints from these places. Stay away from the Mom&Pops. They buy from anybody and anywhere. They get the bottom of the barge here locally.

My .02...

 

I worked for a fuel distributor for ten years, but it's been a while. Like stated above, pretty much all fuel starts out the same. Pure gasoline is no different no matter what company sells it. The BIG difference is in the additive packages that the various companies put in their brand of fuel. This includes additives such as octane enhancers and (the biggest) detergents to keep your injectors, valves, and combustion chambers clean.

The use of ethanol in fuel complicates this a bit. When I sold fuel there was no ethanol in our gas, so I'm not that familiar with it other than my own personal experience (I don't like it).

The companies in my area with the best additive packages, in my opinion, are Chevron, Shell, and Exxon. All three have slightly different packages, but they should all keep your engine as clean as possible inside by reducing carbon build-up. It doesn't matter whether it's 'regular' or 'super' grade, unless your engine's compression ratio is high enough to need the extra octane to keep from 'pinging'.

Basically, if you stick with one of the major companies' brands, you should be getting quality fuel. Avoid buying fuel from stations with no branding and low-volume stations. No-brand stations buy on price-point, so you will almost always get lower quality fuel at them. If you don't need the high-octane gas, don't waste your money on it. There is no real benefit unless you require the higher octane.

 

Well, my engine has been "pinging " for quite some time now. But I haven't really looked into it...

 

If a stock motor pings, it's not due to fuel octane. It's because the EGR system is gone. No 400 ever made it into a truck without one. Your first post said all the smog equipment is missing; that's your answer. Your combustion chamber temperatures are too high (this is hard on the engine).

 

Combustion chamber deposits will also cause pinging.I swapped heads on a 351M and the chambers were caked with crud.The truck ran great on reg fuel(87 octane) after the head swap.Just remember that higher octane fuel burns slower than lower octane which makes it resistant to pre ignition.If your engine starts pinging,and it "used to run fine",then there is another reason it developed a taste for high octane.You could start by checking the timing.Parts stores fuel additives are nothing more than snake oil(petroleum by products,detergents).

 

My 1973 F-100 302-V8, California emissions, was recommended to run Premium Fuel only. It went by engine calibration. If I was to guess, 90% or better was calibrated to run 87 octane that was sold. Only a few really needed Premium high octane fuel. I'd go by the manufacturers recommendation.

The only fuel at that time when the 1973 was bought was Leaded as well.

The switch from lead to unleaded killed it's original engine eventually.