mmarshall

How long have those cars been using Mexican fuel? If those engines don't have knock sensors, piston damage from low-octane fuel doesn't necessarily happen overnight, but when it does show up, it can be serious. Same with carbon build-up. You can sometimes get away with using a few tankfuls of El Cheapo gas without proper detergent additives, but keep it up and spark plugs, fuel injectors, and other engine parts will get carbon/gum build-up, sometimes to the point where the engine will either run poorly or not at all.

Cars that are built to be sold and driven in Mexico are designed for the junk fuel that is sold there. Cars designed and built for the American market are meant for 87-93 octane fuel with detergent.......they can tolerate Mexican fuel for short periods if they have knock sensors, but clearly are not designed for it.

splitfire

iTrader: (6)

how much is premium in so cal now? here in tokyo is 164 yen a liter for premium...

-J-P-L-

After hearing that people are crossing the northern border into Canada to receive medical treatment because in America health care is too much of a luxury , this doesn't surprise me.

yusef

my sister just text me sayin in malibu its 4.99 a gallon.

splitfire

iTrader: (6)

already???? it was like $4 in LA just a few weeks ago but even at $5 a gallon in the state is still cheaper compare to what we pay here in asia

lobuxracer

iTrader: (2)

Actually no, this is completely untrue. An engine will destroy itself in seconds if it detonates and has no means of changing tune to save itself. SECONDS. How do I know? I've done it. More than once. Why? Because sometimes the only way to find the limit is to go past it.

mmarshall

It's got to be awfully severe detonation to ruin an engine that quickly. I'll take your word if you say you've seen it, but I haven't. Usually engines get progressively worse damage to the tops of the pistons from continued detonation. Eventually it can leave a hole.

Lexmex

Wish this reporter had lived south of the border running his vehicle for 6 years and paying the interior of the Republic price, not the border prices that are cheaper to compete with the U.S. (at least until now).

Many of you read my commentary for years about the quality of gas in Mexico. If you do go across the border make sure you fill up a full tank before going across.

However, if you have to go futher south, only use the Premium 92 octane UBA (Ultra Baja Azufre), ultra low sulfur. Still higher than U.S., but an improvement over many years ago. Only nice thing about sulfur was that I found the engine ran a bit cooler. By 2009, Pemex is expected to introduce a low sulfur version of their 87 octane gasoline known as Magna.

There really is a quality difference. My uncle and I would fix an inordinate number of fuel filters compared to what I knew of in the U.S. and injector issues were common. It opened me up to a whole new world about what I knew could go wrong with a motor vehicle.

My RX300 was quite happy to fill up at Chevron station when it came across the border for the first time in almost 3 years.

lobuxracer

iTrader: (2)

It was completely inaudible to the naked ear. No warning pinging, just fractured ring lands on the intake side of the piston from top to bottom, and a nasty crack from the intake seat to the exhaust seat. Your knock sensor will hear it though.

Holing a piston can easily happen in seconds, again, I've seen it (when you get the squish wrong on a two stroke, bad things happen very quickly.) The link here explains detonation exceptionally well and dispels quite a few myths I've seen posted here on CL about pinging and detonation.

lexus114

hahaha,drybacks oh man you something....

gsrthomas

iTrader: (1)

Whats the octane rating over in mex??

Lexmex

There's an 87 octane regular known as Magna and a 93 octane premium labeled strangely enough Premium. The 87 octane is still high in sulfur but by 2009 it is supposed to be very much improved nationwide.