Gasoline
 

ok peeps,

i was at the tunning shop the other day and the guy there said that when an engine (any engine) uses leaded petrol theres a dirty build up in the engine, the best way to clear it is to use 1 tank of unleaded then switch back again. He also said i would notice an increase in performance while using the unleaded.

does this actually work or does this damage the engine...? reason why i ask is because the engine in the Jazz was designed to run on leaded right?

also what about the engine cleaning products that you put in the gasoline tank. do these work or do they damage or do nothing?

Please let me know :)

we dont have leaded gas in the states..

would the engine be exactly the same or not? i cant imagine there would be any harm running it on unleaded would there ?

Sorry we dont have leaded gas until C16 ;)

no street car has been built to run on leaded gas for at least nearly 30 years, and why the hell honda would build a GAS-SAVER car and design it to run on leaded gas...thats just so insanely stupid to think any of that is true, that it killed a few of my brain cells just reading it. NO it was never designed to run on leaded gas.

that guy might be talking about race cars, or old school big v8s pre-cat years. or maybe something running of C racing gas, like a boosted eclipse of something, but no a car for the road

but on a modern car NO, if your in the states you wont find leaded gas, if your car runs on unleaded you'll screw it up if you run anything else

The gas cleaner stuff and injector cleaner usally doesnt do shit. What kind of problems are you having with your car?

you can say its stupid all you want but the dealership said to use leaded gas... here in thailand. thats why i asked. if the dealership didnt say anything then i wouldnt of asked
Also the reason why i asked about the cleaners is beacuse i want to keep my jazz as engine as good as possible. iv had my jazz for a year n half

xtreme,

The purpose of lead in gasoline is to raise the octane number. An organometallic compound like tetra-ethyl-lead is added. When the U.S. phased out leaded gasoline, refineries had to change the formula of gasoline to increase the octane number. In general, it was found that the more compact the molecules, the higher the octane number. I can give a more detailed explaination of octane if you are interested. Today, in the U.S - I don't know about Thailand, all automotive unleaded gasoline has detergent additives to help keep engines clean. The high octane "premium" gasoline has the most detergent additive to help clean the engine. It is possible that by buying brandname unleaded it will contain detergents and clean any residues. As far as performance goes, on paper, I can see how unleaded may provide a small performance boost because it should burn more uniformly due the more compact molecules. It certainly won't hurt anything. Good Luck.

thanks for all your help people...

My dealer said DO NOT use gas additives. They only clog up the engine and can damage your car. My dad used to use that crap and I am convinced that is what caused my catylitic (sp?) converter to go out on my '90 Civic. It ended up costing me $1000.

If you wanna clog up your catalytic converter and screw up the oxygen sensor then use leaded gas. In modern cars those two equipment can get contaminated with lead in the gas. Lead will coat the plates in the cat and render it useless, and will alter the readings on the O2 sensor. Switching back to unleaded won't clear it up. It's already junked if leaded gas was used often.

The only modern engines I know of that uses leaded gas is race bike/car/marine/prop airplane/industrial engines with really high compression and/or forced induction of some kind; or older cars around or before 1974.

The only real issue with older cars designed for leaded gas running unleaded is exhaust valve recession (sink or seat wear). Which is quite minute unless the engine is running under high load and speed all the time.

So your car wasn't designed before 1974. It's not supposed to run leaded gas. Maybe that dude at the dealership has a hopped up 1974 Toyota or Datsun... but whatever he said it's not true for your car.

The off-the-shelf additives for gasoline are "detergents" and/or "octane" booster. I haven't seen conclusive studies if those cleaner type stuff works (when thinking in the context that modern gas has detergents already, how much more do you need to make a real difference is the better question). Octane boosters do help if you're knocking a lot.... like running 16+ psi of boost in a Grand National. :D

Also, there is a "lead replacement" additive that can be bought for older cars (pre-1974,) also a "gas stabilizer" that can be added to retard gas aging (works for old lawn mowers and motorcycles, etc. that are stored for a winter season.) DON'T USE THEM IN YOUR Fit/Jazz either! They will also probably ruin your catalytic converter.