Anyone ever thought of running or have ran AVGAS (100 octane) in their XJ? Wondering how it would do for plugs, cat, o2 sensor and stuff. I might be able to get it for free at a local airport so they don't have to pay to have it hauled off after they check for water.

 

Haven't done it personally as I care about my vehicle more than that. The 4.0L is not a racing engine lol.

Aside from operating a vehicle with leaded fuel that was intended for unleaded possibly being illegal in a few jurisdictions, you can expect the TEL to leave deposits in the engine itself, foul the spark plugs, ruin the O2 sensors, and destroy the cat.

 

It's 100LL, so its low lead, but was just curious...And I'm sure it's just one of those things that you just don't talk about if you do it. I mean how is someone gonna know if you run it unless you blab about it.

 

don't do it

 

The lead in the fuel will ruin the catalytic converter and the high octane will not make your low compression 4.0 run any better.

 

Don't use it in a 4.0.. Unless its built... I have put I'n a push mower and it didn't mess it up at all and still use it time to time... I work at a airport so I deal with it daily

 

Being an aircraft mechanic and thus perpetually broke, I've run surplus avgas in cars before. Only cars it really works in are old VWs and Porsches, because they're also opposed, air cooled engines designed for leaded fuels. Besides, you just won't see any extra power from avgas in a computer controlled engine like ours. It's just not worth it.

 

I agree with the others, no upside but plenty of downside. Even if you get it free, replacing the cat will cost you money

 

So will the new valves

 

I have used it in other cars but never in my Jeeps. The cars that I did run it in were built for street racing and it did make a difference. I wouldn't recommend it for a stock engine.