Gas Question: Premium vs. 100% Regular

dduelin said:

Leaded gas is not bad for valves. Tetraethyl lead is actually good for valves and valve seats. The problem with it is that it will destroy the effectiveness of catalytic convertors. That is why it was phased out of auto gas in the mid seventies when CC were introduced to help control emissions.

Click to expand...

So we can run leaded gas with after market exaust pipes(no catalytic convertors)

Smallville said:

I think you may have some terms confused.

Click to expand...

Did I really? I believe the gentleman in reply #12 agreed with the intent of my message. Regardless if I was not exactly spot on with the terminology, the answer to the original question remains that running high-octane fuel with 10% ethanol in the ST1300 is less of a financial risk than running low-octane fuel without ethanol.

Here is some information from my 2003 manual.

View attachment 92 octane.pdf

View attachment oxy fuel.pdf

You decide if it is safe to run 10% blended fuel.

Kevin

hoowasat said:

Did I really? I believe the gentleman in reply #12 agreed with the intent of my message. Regardless if I was not exactly spot on with the terminology, the answer to the original question remains that running high-octane fuel with 10% ethanol in the ST1300 is less of a financial risk than running low-octane fuel without ethanol.

Click to expand...

No harm intended. Simply providing some infomation so that you may be better informed. Use it as you wish.

Gandolkf said:

So we can run leaded gas with after market exaust pipes(no catalytic convertors)

Click to expand...

Well, I am pretty sure it is illegal inasmuch leaded gas is not taxed for on-road use. It is dyed for off-road use.

Good discussion and lots of insight from riders with real experience. Here's a related question. Is using lower octane in the winter (cooler temps) safer on your engine than in the summer? At first thought, it seems so. I've never done it, but thought about it to save money -- my car requires 91+ octane, too. As fuel prices are starting to rise again, the temptation (during this time of year, at least) is very strong.

I have been running mostly 87 octane with up to a 10% alcohol mix. So far the only ill effects are when I forget to downshift before grabbing a handful of throttle at low speeds (particularly when the air and engine are hot). Normally I'm a very conservative rider, so I don't think that the bike has any pre-detonation when cruising out on the road. I have tried mid-grade (89 octane) and haven't noticed any increase in fuel mileage. I am reluctant to spend another $2.00 per tankful on the highest octane, but I might give it a try to see if there is any difference in performance and fuel mileage.

omniron said:

Good discussion and lots of insight from riders with real experience. Here's a related question. Is using lower octane in the winter (cooler temps) safer on your engine than in the summer? At first thought, it seems so. I've never done it, but thought about it to save money -- my car requires 91+ octane, too. As fuel prices are starting to rise again, the temptation (during this time of year, at least) is very strong.

Click to expand...

Actually the opposite. Colder air is more dense. As it is compressed the pressures run higher with colder air than hotter air which is thinner. This is why many cars and trucks with turbos use intercoolers. The air is run through a turbo to make it more dense. This heats the air as it is compressed. Then it runs through an intercooler which is basically a big radiator that air moves through rather than coolant or oil. This cools the air making it more dense and then it goes into the engine where it is compressed again by the engine and ignited. This is done to make the air as dense as possible to produce more power when it detonates.

Smallville said:

No harm intended.

Click to expand...

No offense taken, and I appreciate your concern. <Ken>

Interesting discussion

I figure if I spent $12,000 for a bike, I will put in whatever is recommended by the manufacturer. If it costs me another $2 per tank, so be it.

Hi All:

Interesting discussion.

Having worked on many automobile injection systems, I'd rather run clean regular in my ST and risk engine damage (no low RPM rolling on the throttle, just downshift and get the engine speed up) than run the stuff that will disolve fuel system components.

100% chance of fuel system damage if it sits
?% chance of bearing or pistion damage if running higher RPM and lower octane.

JMOICBW

Eat Sleep Ride
Woodwork

Wow, look at this subject. We're on page 4 and has the real question been answered?? All I'll say it just makes me LOVE my ST1100 that much more. lol I fill up with 87 all the time, it runs GREAT, and I usually get around 50 mpg. Did a 430 ride to east Texas on Saturday, running 75-80-85 most of the time and still averaged 47.2. I ain't gonna complain 'bout that.

woodwork said:

Hi All:

Interesting discussion.

Having worked on many automobile injection systems, I'd rather run clean regular in my ST and risk engine damage (no low RPM rolling on the throttle, just downshift and get the engine speed up) than run the stuff that will disolve fuel system components.

100% chance of fuel system damage if it sits
?% chance of bearing or pistion damage if running higher RPM and lower octane.

JMOICBW

Eat Sleep Ride
Woodwork

Click to expand...

Just curious, you say there is a 100% chance of fuel system damage if it sits. So what damage can you show has been done to a 1300 because it was using E10 or sitting with E10????

I have been around here for quite a while and have yet to see any discussion where any proof of damage can be shown from the use of E10. Sure I know what ethanol does to fuel delivery systems and engines if they are not made for using it. However those issues largely come up when you are dealing with much higher concentrations of ethanol in the system. I am talking E85 not E10. There have been no documented evidence that running E10 will cause any problems in the long term on a 1300.

As I mentioned before the only ST that I have seen with anything that resembles any track record that E10 may be an issue is with the fuel cutoff on the ST1100. There have been way too many failures of these diaphragms both new and old to chalk up to bad luck. The fact that the part in question is in direct contact with the fuel, made of rubber and is very thin would all support the idea that if there is a weak spot it would be the point of failure. The 1300 doesn't have this though.

The only thing that might be attributed to gas is that some bikes have had issues with carbon build up in the valve guides. From what I have read about Ethanol and the effects on an engine this isn't typically what you would see. The fact remains that part of why our gas is so expensive is that every state, county and city can set their own policies when it comes to additives in fuel. So how can we say we are comparing apples to apples when we only look at one of the many additives in gas? It is entirely possible that those carbon deposits came from some other additive.

All this said, I still try an run E0 when possible. I won't go out of my way for it but I do so not because of fear of damage to the engine but rather because I get better mileage on it. It is a proven fact that there is less energy (BTUs) in Ethanol than Gas. That is why fuel economy drops when you run E85 in a flex fuel vehicle. While the difference in economy between E0 and E10 is only 1-2 MPG in my experience, why not run E0 if it is readily available and the same price.

For me 87 pings 89 and up doesn't.
So no 87 here.

I don't think there is a source without ethanol locally.

+1 on the AvGas poisoning the cats.

st1300r said:

For me 87 pings 89 and up doesn't.
So no 87 here.

I don't think there is a source without ethanol locally.

+1 on the AvGas poisoning the cats.

Click to expand...

I thought it just made them loco?
Ethanol sure does.

That would be the easiest decision I ever had to make. I always ran 87 ethanol here (no ethanol free here except at marina$) and never had a problem. It would pre detonate some if lugged down. I attribute that to rider error or laziness downshifting. My new bike calls for 87.

I would take anything ethanol free over any octane. JMHO

Hmm ... My 2006 owner's manual also states that Honda "recommends" unleaded 92-octane or higher, and specifically suggests avoiding lower octane fuels. The Honda engineers do not ask their consumers to buy higher-priced fuel for no reason, and I will fuel my bike in accordance with the owner's manual. Besides, not all engine knock is audible. Meanwhile, I will save this thread for later reference so I may identify the bikes I must avoid should I be in the market for another example.

Well from a technician's standpoint- I don't see either choice causing any serious issues for most of us on this site. Yes, the 1300 will adjust to most fuels. Notice Honda suggests (doesn't require) higher octane fuel. For max. power and efficiency, higher octane fuel should be used. I highly doubt any damage will be done by running 87 octane. In comparison, if you run ethanol fuel, there is a good chance of gumming up the pump, injectors, or fuel pressure regulator if the bike sits for a long period of time. But how many of us on this site let our bikes sit?

I pick the lesser of the two evils and run premium fuel whenever its available. The station closest to my house only has 87, so if I need fuel when near home, I don't lose sleep over running 87, but I try to avoid it if possible and convenient. Running premium gains me a few mpg, so the mpg savings pays for the extra cost at the pump- so there is really no reason to run 87 if I can help it.

Jim

As a former Valkyrie owner, I can attest to damage from E10 to the fuel system. First, ethanol caused the vacuum petcock to fail, flooding the left bank of cylinders. I got the hint something was wrong when I opened the garage door (Mebbe shouldn'ta used the electric opener) and smelled/saw fuel dripping from the left collector/muffler joint. Had 6 carbs rebuilt @ $150 each after ethanol caused the failure of the carb seals, only to have them gum up again in 4 weeks of storage with Sta-bil and 89 octane on board, cost to flush $100 each. That's when I decided that it was time to move on to fuel injection...

I'm in the same boat as UNTMatt, you can't find non-ethanol around our parts due to EPA smog/air quality mandates for the D/FW metropolitan area. Our bikes (or at least my '98 Valk) were designed before ethanol replaced MTBE as an additive for air quality purposes and the manufacturers are a little behind the curve coming up with a solution since they can't "positively" link the component failure to ethanol. I'll keep putting in the higher octane stuff and running some Seafoam or Techron every so often to deal with the deposits. I read in Motorcycle Consumer News that the manufacturers are concerned about a mandated bump from E10 to E15 (to reduce our dependence on that "furrin" oil and promote good ol' American CORN) and the effect that will have on all engine systems since they weren't designed to operate at that ethanol concentration.