No more MTBE

jhm · February 2, 2004

I dont know if this is a fed thing or state, but all our gas stations cant sell gas with MTBE. Instead they put in 10% ethanol. I SWEAR I notice a difference at some RPM's. It isn't noticeable during forced downshifts when passing, etc, but during normal driving, say going from 30 to 50 mph, I notice a lag in power. I am all for a clean enviroment, the MTBE was shown to pollute ground water, but somethings gotta be done to fix this. I am thinking maybe going to a higher octane, but will it make a diff or just suck more money out of my already strained wallet?????

99-2door · February 2, 2004

I dont know if this is a fed thing or state, but all our gas stations cant sell gas with MTBE. Instead they put in 10% ethanol. I SWEAR I notice a difference at some RPM's. It isn't noticeable during forced downshifts when passing, etc, but during normal driving, say going from 30 to 50 mph, I notice a lag in power. I am all for a clean enviroment, the MTBE was shown to pollute ground water, but somethings gotta be done to fix this. I am thinking maybe going to a higher octane, but will it make a diff or just suck more money out of my already strained wallet?????

MTBE has 19% less energy than gasoline

Ethanol has 34% less energy than gasoline

MTBE was mixed at 15% giving total of 2.9% loss

Ethanol is mixed at 10% giving total loss of 3.4%

at 300HP that is 1.5HP difference, doubtful that you can tell the difference

Most likely you are feeling the difference in winter mix and summer mix, since the winter contains oxygenates in some areas. Or the fact that your engine is simply more experienced now than when MTBE was used.

jhm · February 2, 2004

Could be the oxy, I seriously doubt the extra 2k miles on the clock since the switch has worn my engine to the point that acceleration is compromised. I may try 89 octane to see if there is a diff. I been using Getty fuel exclusively, now I found out they were bought out by a Russian oil co. Maybe the Ruskies are suppling cheap fuel!

February 2, 2004

hey 99-2door, check your math. I have no idea if the MTBE vs ethanol mix numbers are correct, but my calculator says 3.4% of 300hp is 10.2 not 1.5hp. I won't say everyone can feel the difference, but there are a lot of companies out there selling stuff like air filters, MAF systems, etc that are promising us that we can. I hope they're right.

MN Z-71 · February 2, 2004

In most areas there is no difference between winter gas and summer gas. The oxygenates (99-2door) that you speak of is either MTBE or Ethanol. There are no other oxygenates. The use of MTBE has been banned so ethanol is the only option.

Here in MN we used to only get oxygenated gasoline in the winter. But for several years now we have been getting it year-round.

I can honestly tell you that there is no discernable difference between straight gas and gas with ethanol. There will be a VERY minor mpg difference. Maybe 1 mpg at the most.

Going to higher octane will not help either, this is a very common misconception about octane ratings. Octane is merely a measure of gasoline's ability to ignite. The higher the octane rating, the harder it is to ignite. As a result high octane gas actually has a lower energy content then 87. This is why high performance engines require the use of high octane gas, high compression engines will ignite 87 octane gas by compression (like a diesel) before the spark ignites it. This is where pre-detonation (pinging) comes from.

jhm · February 2, 2004

I am pretty sure the added ethanol reduces engine performance. I checked a govt document on ethanol as a replacement for MTBE and although it is quite technical, written by a chemist, it states "ethanol does not blend well with gasoline and reduces the volatility of the gasoline". I seem to recall something in my owners manual stating not to use ethanol fuel. I will have to check on that, but I know my truck does not respond to the throttle like it did with MTBE.

99-2door · February 2, 2004

hey 99-2door, check your math. I have no idea if the MTBE vs ethanol mix numbers are correct, but my calculator says 3.4% of 300hp is 10.2 not 1.5hp. I won't say everyone can feel the difference, but there are a lot of companies out there selling stuff like air filters, MAF systems, etc that are promising us that we can. I hope they're right.

Hey, check your math smart guy!

The difference between 2.9% and 3.4%, which is the issue here, is .5%

99-2door · February 2, 2004

In most areas there is no difference between winter gas and summer gas. The oxygenates (99-2door) that you speak of is either MTBE or Ethanol. There are no other oxygenates. The use of MTBE has been banned so ethanol is the only option.

That's what I said, I just figured anybody who knew what MTBE was would know it is an oxygenate.

As far as higher octane fuel not producing more power....not necessarily. True it doesn't contain more power..but it may help produce more, especially in a fuel injected vehicle.

A moden engine contains knock-sensors which retard the timing in order to prevent knock in the engine. A higher octane provides a higher resistance to knock allowing the engine to run with a more advanced timing providing better acceleration and such.

jhm · February 2, 2004

I may have stumbled on something. At greenfuels.org there is info on ethanol and it states modern engines can run on up to 10% ethanol without modifications. This leads me to believe that anything more than 10% would adversely affect performance. Who knows if all fuel sold does not exceed this. There has to be some tolerance. Maybe the fuel I have been getting exceeds 10%. Also, they say the ethanol releases deposits left in the fuel sytem by other non-ethanol fuel. They suggest changing the filters more frequently because the gunk can clog the filter causing poor performance. All I know for certain is I notice a diff with the ethanol fuel I have used the last 3 tankfulls.

dcairns · February 2, 2004

I am pretty sure the added ethanol reduces engine performance. I checked a govt document on ethanol as a replacement for MTBE and although it is quite technical, written by a chemist, it states "ethanol does not blend well with gasoline and reduces the volatility of the gasoline". I seem to recall something in my owners manual stating not to use ethanol fuel. I will have to check on that, but I know my truck does not respond to the throttle like it did with MTBE.

Not sure, but maybe you don't understand what volitity is. Volitility is just the vaporizing ability, not it's performance ability.

JackB · February 2, 2004

Alcohol content affects motors differently. Some motors don't mind, some do. Generally the higher the CR, the less you will notice a difference with alcohol.

joeman2199 · February 2, 2004

maybe this is different, but i read somewhere that ethonol sometimes helped engine performance, or maybe thats just the case with E-85 (my truck soposedly was made to use gas or E-85 by gm). personally i havent used it, i know that its better for pollution, when it comes to my area if it does, ill have to give it a shot.

but then again, MTBE was the reason sunoco had 94 ultra gas by me when i was in new york. now the 94 is gone, and the 93 has gone up. so i guess if you look at it that way, ethonol is bad.

JayMan · February 3, 2004

Well, Canadian fuel companies have had ethanols for some time now. When you consider the alternative of canuck regular unleaded which has MMT (Methylcyclopentadienyl Manganease Tricarbonyl), and I'd prefer keeping the manganease out of my O2 sensors and cats.

PetroCanada/Mohawk sell ethanol blends up to 15%, which GM claims is safe to use. It's way cheaper too, thanks to the subsidies, though folks with older FI cars and certainly those with carbs will have a lot of problems.

Running 92 octane ethanol gas my truck feels a bit peppier, gets the same MPG, and the oil stays cleaner. When I first started using it in 2001, the oil turned black quickly, so I had a Motorvac to get the rest of the deposits out.

After two years on ethanol, so far so good. I change the fuel filter every fall anyway, so that's not a big deal to me.

tmoreau · February 3, 2004

I live in the chicagoland area so my truck sees a steady diet of ethenol. I swear my truck like road trips, that nice clean unmolested fuel sure makes it run happy. Something to watch out for, ethanol can be hard on the injectors causing them to gum up or clog much more frequently than regular gas. I run some fuel injector cleaner through about every six to twelve months so I dont have to fork out cash for new injectors in a few years.

A relative of mine worked as a technician at a chevy dealer in wisconsin then moved to this area, he misdiagnosed a few cars before learning that the fuel around here is he!! on injectors causing them to fail (or get clogged beyond saving) many times more frequently than he was used to.

jhm · February 4, 2004

All states are on line to phase out MTBE by the end of this year. They didn't do it all at once because there would not be enough ethanol available. It is a fact that the ethanol will be more prone to clog filters and injectors than fuel with MTBE. I will be changing the fuel filter anually (not going to go crazy over it) and throw in some cleaner twice a year. One good thing is the ethanol does away with any need to add dry gas, since the ethanol is more efficient absorbing water than isopropyl alcohol.