Gasoline re re re revisited

Fri Oct 28, 2005 5:12 pm

I hesitate to open yet another gasoline post, but I must tell this. My 2000 S-10 V-6 pickup has been running on regular gas since the prices started going up about a year or so ago. I used to run premium, just because I think it is cleaner. Well today...since gas proces are not as expensive, I decided to run premium gas. Whoa the difference! smother, more power and no hesitation. I keep up on the maintenance, so that is mostly ruled out. I spoke to a friend who has a S-10 Blazer and he has had similar results. I bring this up in the Cub section, because I am going to try several different fuels in the Cub. I have aquired 80 octane avgas, 100 octane avgas. I will try those fuels against regular, mid and premium gas. My cub runs just fine on the regular, so I am doing this just for the helluvit. I know John P has had issues with cheap gas as well as Bill Poor, but it has just now really affected me and I was wondering too if anybody else has had issues of late. My fingers are tired now.

Fri Oct 28, 2005 5:40 pm

I have aquired 80 octane avgas, 100 octane avgas. I will try those fuels against regular, mid and premium gas. My cub runs just fine on the regular, so I am doing this just for the helluvit.

How will you measure the results of each type of fuel?

Fri Oct 28, 2005 6:00 pm

Probably just mow or something, I wish I had a dyno! But I think I will be able to feel the differences in behavior unless they are very subtle. 80 octane is no longer available, so its test os moot, but I think it will burn better than 87 pump gas.....just a hunch

Fri Oct 28, 2005 6:19 pm

Hey Carm,

I have ran regular unleaded in my 2000 Sliveraro extended cab, (87 octane) ever since it was new and it now has almost 61,000 miles on it and NEVER given one single problem ever. Excellent power, no pinging, or any hesitation. It has a 327 with 4 speed automatic and it's nothing to see it hit 26 MPG pulling a trailer with both the four-wheelers. A couple less pulling the Cub, but still real good performance. It would drop down to 15-17 while pulling our big old antique heavy camper, that's with the tow/haul switch on and not in overdrive.

HOWEVER, on my 88 Harely-Davidson, it hates 87 ocatane and throws a complete fit whenever I use it. The darn thing prefers highest ocatane fuel from Texaco gas. I don't know what they put in it, but it runs like a scalded [blank] ape.

My 54 Chevrolet with the original in-line 6-235 engine is the same way, it pings, farts, bucks, belches, sneezes and hesitates with the low grade stuff too. But then again it grew up on old Eythel. :lol: same good old stuff these Cubs were rasied on as well. :wink: I also add a pint of lead subsitute to my about every other tank on my old truck, I don't bother with it on the cubs.


Fri Oct 28, 2005 8:32 pm

Carm, Boy I sure am glad the torch was passed on this one. I was feeling more and more discredited everytime I posted. And I wasn't about to post on this topic anymore. I fiqure if there really is something to this fuel thing then time and events will bear out.
So as we say over here at the flight dept. Get out your bunsen burner and let me know your findings LOLOL :lol:

Fri Oct 28, 2005 9:32 pm

Carm I did a test 4or 5 years ago on how much it cost me per km . and
with the extra milage that I got from high octane it came out cheaper on both
my van and suv.

Sat Oct 29, 2005 10:55 am

jniekamp wrote:
HOWEVER, on my 88 Harely-Davidson, it hates 87 ocatane and throws a complete fit whenever I use it.

John try race fuel one time. its expensive but harleys love it.

Sat Oct 29, 2005 1:14 pm

Scotty D wrote:John try race fuel one time. its expensive but harleys love it.

LOL, what ya trying to do to me Scotty :?: I get it spoiled on raceing fuel and it won't even want to run on the high stuff from the pumps.

I'll compare it to me having prime rib every night and then all of a sudden I have to eat a plain old nasty hot dog. :lol:

BUT your right, it do run good on it and it IS expensive. :wink:


Sat Oct 29, 2005 2:29 pm

I never EVER buy anything but 87 octane, now that I don't own any diesels. I've put it off as long as possible, but I had to get the chain saw out today. It was last run over 3 years ago and just shut off and put on the shelf. I dreaded having to get it running. I'll freely admit I had to pull the rope more than I remember and had to give a whiff of starting fluid... but it started and runs fine on that old 87 octane.

If I could think of a good reason, maybe I'd start that old string trimmer that has about 10 year old gas in it.

You guys are teaching your stuff to eat too high on the hog!

Sat Oct 29, 2005 3:26 pm

Scotty D wrote:
John try race fuel one time. its expensive but harleys love it.

Hey I was given over 50 quarts of new unopened oil from our local landfill plus other oils. Along with the oil there was a gallon of remote-control hobby car gas engine racing fuel. Anybody know of a good use for this gallon of R/C racing fuel?.

Sat Oct 29, 2005 3:39 pm

I was always under the impression that the higher octane fuels just helped with those engines that had issues with pre-ignition (dieseling), like higher compression designs, no? I would imagine that some engines that detinate on the compression stroke do get better mileage from the higher octane gas, but many engines have no such problems. I would also imagine a Harley having compression out the wazzoo, and pre-ignition being something of a problem.

Oddly enough, Ethanol, (which is a big component of racing fuel), has a very high octane rating (I believe greater than 100). But those of us who drove during the late 70's will remember very well that ethanol blends did not necessarily give us very good mileage (gasohol). Of course the engines of the 70's seldom had pre-ignition problems while running, anyway (some of them were devils to shut off, though, with all that hot carbon buildup in there...LOL)

On a related note, how many of you guys are adding some kinda lead additive to your gas for the older farmalls?

Sat Oct 29, 2005 7:59 pm

I tried the high octane experiment on my 57 loboy after I got it. I used the C-3 mower and the fast hitch moldboard plow with 110 octane racing fuel. The only difference was in my wallet.

I am certain that once I have the engine redone inside and out, it will be running on full torque and horsepower with regular fuel for another 30+ years.

Sat Oct 29, 2005 8:51 pm

Ah, looks at it thisa wayyy.

Ifn I puts reglar fuel in mah tummy and ah runs ohkay, then mah trahctor ain't gittin any of that thar high tech stuff.. reglar is good nuff fer me Cub ifn it's good nuff fer me :shock: 8) :wink: :lol: :lol:

Sun Oct 30, 2005 8:06 pm

I agree with everyone of the previous posts-however I just got to say- last month I tried to use my dads rototiller that hasn't run in years. It wouldn't run hardly at all. Found a bunch of crystalin stuff in the tank that had plugged the fuel inlet passages. I've seen that before in units that have sat alot. Better quality fuels don't have that problem which is why I will use them in units that sit around alot. So I won't have to fus with them when I want to use them next.

Mon Oct 31, 2005 11:11 am

The octane number has nothing to do with BTU output or power. In a nutshell, octane ratings determine a gasoline's ability to resist ignition under pressure. Fuels with higher octane ratings can be used in higher compression engines without knocking. It's the higher compression that adds power, not the octane rating.

Ethanol has high octane ratings because of it's chemical and physical properties, just as tetra ethyl lead gave leaded gasoline higher octane ratings than the unleaded "white" gasoline that Cubs were designed to run with. But ethanol has considerably fewer BTUs per unit than gasoline so power suffers as well as economy.

A high performance, high compression engine running a low octane fuel will produce less power due to pre-ignition creating a lousy explosion in the combustion chamber. Many performance problems in engines requiring lower octane gasolines can be traced to deposits in the combustion chamber that increase compression or create "hot spots" that encourage pre-ignition. Higher octane gasoline solves those problems temperorily because of it's resistance to ignite under pressure and heat.

GM had a product available called "Top End Cleaner" that claimed to remove those deposits.