UNLEADED GAS

Old-Biscuit wrote:
Those that have gasoline engines.......

Not being cute or funny.

Modern computer controlled engine fuel system rarely require premium grade fuel.
All grades are unleaded. But regular 89 octane is the norm.
Blended grades (with ethanol) will get lower mpg due to the lower BTU content

That's a gas! v :B

Let's see if I've got this right.

All Knowing Uncle Sam makes the petroleum industry blend ethanol into gasoline to purportedly cut down on pollution.

Then, users of blended fuel end up, burning MORE fuel to travel the same distances as with non-blended gasoline?

:h

bsinmich wrote:
There are a few places where you can get real leaded regular yet. We get some for our emergency generators in the condo. The places I have found are close to boating areas and it does cost more. We use it because it does not deteriorate as quick as the unleaded with alcohol.

I think you'll find the fuel at the marina is still unleaded. It just doesn't have the 10% ehtanol added. The EPA got the lead out many years ago.

There are a few places where you can get real leaded regular yet. We get some for our emergency generators in the condo. The places I have found are close to boating areas and it does cost more. We use it because it does not deteriorate as quick as the unleaded with alcohol.

wa8yxm wrote:
What can happen is over time carbon deposits build up in the combustion chambers and you may start to hear a bit of "rattle" (Pre-ignition knock) which goes away if you upgrade the fuel to mid or premimum.

HOWEVER, this means you need service, MAJOR service.

Nah, just get the engine good a hot and mist water down the intake. When the water hits the cylinder head, it will boil the carbon off. Worked great on my first Goldwing.

One of the problems we have is the labeling of premuim vs regular. We associate the word "premium" with higher or more pure. In fact the opposite tends to be true. The octane rating is exclusively a measure of the ignition temperature. The lower octane means that it ignites easier. That is why an engine that is designed to run on regular will get worse mileage running on premium. Now it is true that from a design standpoint, raising the compression will squeak out more power, but when the compression is raised, the fuel may self ignite. High compression really is a trade off, but a good one, as the gains of the higher compression do outweigh the losses from being required to run gas that is harder to burn. The trick with more recent designs is fats burn heads, which compacts the fuel in one small area, as opposed to being spread out over the whole piston. This helps prevent self ignition and allows higher compression. For instance, the 8.1 liter BBC has higher compression than the old 454 could get away with, because of the head design.

I think it has more to do with the octane rating, mine says 87

wa8yxm wrote:
Most all "Stock" gasoline engines made in many years (LIke the 1970's) were designed to use Regular grade. And at some point in the 70/80's they made them all use No-Lead, and subsequent to that leaded regular has become very hard to find.

ANY "Stock" engine made this century should be happy with regular no-lead UNLESS it is in need of service.

What can happen is over time carbon deposits build up in the combustion chambers and you may start to hear a bit of "rattle" (Pre-ignition knock) which goes away if you upgrade the fuel to mid or premimum.

HOWEVER, this means you need service, MAJOR service.

ON older engines with breaker points as the timing changed due to wear of the system.. Fuel needs sometimes changed.

However... Modern engines use a very very precise hall effect sensor. it does not "Wear" like points did.

You are of course speaking of gasoline engines used in Class A and C motorhomes, not all vehicle engines at large. There are a great many engines outside of motorhomes that REQUIRE fuel with an octane rating of 91 or more. I own 2 of them.

Now the V10 in our motorhome is quite happy on 87 as required by Ford. My GT and my Spyder would not be so happy.

Most all "Stock" gasoline engines made in many years (LIke the 1970's) were designed to use Regular grade. And at some point in the 70/80's they made them all use No-Lead, and subsequent to that leaded regular has become very hard to find.

ANY "Stock" engine made this century should be happy with regular no-lead UNLESS it is in need of service.

What can happen is over time carbon deposits build up in the combustion chambers and you may start to hear a bit of "rattle" (Pre-ignition knock) which goes away if you upgrade the fuel to mid or premimum.

HOWEVER, this means you need service, MAJOR service.

ON older engines with breaker points as the timing changed due to wear of the system.. Fuel needs sometimes changed.

However... Modern engines use a very very precise hall effect sensor. it does not "Wear" like points did.

Big1Dog wrote:
For years 2000 and up, what Class A MHs use REGULAR unleaded gas???

All use REGULAR unleaded gas. The motors are designed for regular grade, run better on regular grade, and any other grade of gas is wasted money. Ethanol is the problem.

:) you mean the stuff we all pay a higher price for at the pump to compensate the oil companies for no longer adding it?

I've been using unleaded fuel in all my rigs since I started RVing in 1976!