2 stroke gas in a 2.5 TJ?

If diluted with a nearly full tank of fresh gas, pre-mix will NOT screw up anything in your engine. A 50:1 mix represents only a tiny amount of oil - less than 1 ounce per gallon of pre-mix. I have done this for decades with no ill results. I also dispose of slightly stale fuel in the same manner.

Don't put in more than a gallon or two of premix into your small TJ tank.

John Davies

I wouldn't do it. First, how many gallons of premix do yiou really have laying around? You don't have more than a few gallons, and this isn't going to get you more than about 100 miles, if that. And, you'll be needing the premix for its intended uses later on anyway, and the odds are that you'll have to replace it at a higher cost than you bought it for.

Second, there is a real chance that you'll do potentially serious damage to your TJ. Back in the '60s, a little premix wouldn't be a problem, but today's engines have lots of sensors and stuff that won't enjoy the extra oil in the gas.

I'd just bite the bullet, and try pressing the pedals as softly as I can.

50:1 is 2 1/2 ounces per gallon (2.56). I don't believe you've been doing it for decades in a 2.5 TJ.

40:1 is 3.2 ounces per gallon. 50:1 works out to 2.56 ounces of oil per gallon of gas.

Divide the number of ounces in a gallon, 128, by the dilution ratio, 40 or

50, to arrive at how much oil goes into the gallon of gas. I only bring this up because the actual amount of oil needed to attain the ratio of 50:1 is more than 150% greater than the number number you gave.

Good thoughts. A few mentioned the sensor "rumor" - what sensors specifically are affected by 3 ounces of 2 stroke oil per 15 gallons of fuel and what does it do to them?

An under lying reason for wanting to do this is to dispose of some old premix I no longer need.

Rich M

98TJ

...and add a gallon of 50:1 to 10 gal of gas and you have 500:1 or ~.256 oz/gal. Probably that much rat piss and other foreign contaminates in gas already. ('cept here in CA. Our gas is special *g*) The sensors will never know...

There is no sensor that would be negatively affected by premix oil in any vehicle I know of. If the gas is stale or dirty though, there would be problems. I have added premix oil _on purpose_ to late model vehicles at the full 100:1 ratio and never had a problem.

If it's reasonably fresh, I would pour it through a filter funnel into my vehicle to burn it off and replace it with fresh gas for next season. Ultralight pilots flying two stroke engines do this all the time. Even in FFV's with ethanol or methanol sensors.

Thanks for putting the sensor myth to rest. It's amusing to watch the rumor perpetuate - I mentioned it, then others parrot the warning, yet no one seems to know what sensors they are talking about or why a miniscule amount of 2 stroke oil would affect them. Didn't the old stolen kidney myth get started on Usenet too? :^)

Rich M

98TJ

I always throw a once in a blue moon squirt of 2 cycle oil in all my vehicles with in-tank gas pumps on the theory they could use the lube. Since I never have to change pumps it must work!

Rich M proclaimed:

No, just the Choking Doberman.