Ask Sarah: O-ring a block, AEM water/methanol kit, importing a Tsuru
AEM water/methanol injection
AEM water / methanol injection 

Hi Sarah,
I have a one gallon AEM water/meth injection kit. I was wondering about the mixture. When referring to a 50/50 mix for water/meth is this calculated by weight or volume?
Bruce Alexander


water/methanol injection kit
The water/methanol mixture is injected ahead of the throttle body.

A water/methanol injection system is intended to keep the chances of detonation down. In gasoline engines, pre-ignition occurs when the air/fuel charge ignites before the spark plug fires. A water/methanol injection releases an atomized mist of water/methanol to the charge. The mixture absorbs heat, reducing inlet air temperatures making pre-ignition less likely to occur. Water is more capable of cooling an intake charge than simply adding methanol but methanol acts as an octane booster. Using a 50/50 mix of the two allows your engine to run more advanced ignition timing and/or boost pressures and provides more horsepower when tuned well. In turbo diesel engines, a water/methanol injection will reduce exhaust gas temperatures and increase combustion efficiency for greater power delivery. 

The suggested 50/50 mix is by volume but it doesn't really matter. The real reason for adding water to methanol is to keep from transporting a bomb. Methanol is a volatile, flammable liquid. Unlike gasoline or diesel fuel, methanol is miscible (can mix well) in water and hygroscopic (absorbs well). It is still flammable even at 5 parts water to methanol. Someone could technically run 100% methanol in a water meth kit and tune their air/fuel ratio correctly to see massive gains but that plan might go down in flames; literally…


Hi Ms. Sarah.
I have your book on Nissan Performance (excellent resource). I'm considering heading down to Mexico to purchase a B13/V13 Sentra/Tsuru. How can I go about this?

David Nau


B13 taxi
¿A dónde vas?

The B13 was sold in the US from 1991-1994. After the new B14 model was released, those versions took the name Sunny (instead of Sentra) and the B13 continued production in Mexico, Asia, Africa, the rest of the Americas, and the Middle East. The B13 is still one of the most popular cars in Mexico often ferrying tourists from resort to tourist destination. In order to buy one you should:

–    Learn fluent Spanish (especially slang)
–    Get fitted for a Kevlar outfit
–    Find a fixer or a dozen (preferably former Navy seals or DEA agents)
–    Book your flight, find a ride, or in my experiences take the trolley from San Diego to Tijuana and beyond and learn some words 6 years of Spanish never taught…

I know you want a hot car, but to keep from picking up a “hot” car. Based on what I’m sure is a very low likelihood of this occurring (“Sarah”-casm), there is actually a website to help you check this:

Verify all the taxes are paid. Take the owner (with valid ID), the keys, and original bill of sale, as well as the tarjeta de circulacion to a notary. The tarjeta de circulacion is like a passport for a car. If it’s valid for the length of time you’ll be driving the car in Mexico, you can use it with the previous owner’s name. Getting the tarjeta issued in your name requires a few months, a few hundred-ish dollars (bribes make things happen faster), and the FM2/FM3 form which says you are living or employed in Mexico; an FMT is a Tourist Visa. Don’t forget mucho dinero, most of it hidden for proper negotiation tactics.  And this is where knowing the difference between ano y año will save you some time and money!

But if you’re planning to import it a los Estados Unidos, buena suerte. It’s very easy to go about it the reverse way and export a car to Mexico- buy a popular tuner car, modify it to draw some attention, show up at a street race or leave it parked on the side of the road, and someone will take care of getting it into Mexico for you!  Or at least to a chop shop where it will be pilfered of its valuable guts… Of course, the legal way would cost a hefty tax bill. But it's also difficult to import a car to the US.

  1. To process and license a new vehicle, you must have the FM3, a utility bill proving residence, CURP (a unique 18 character string that identifies you as a citizen or resident of Mexico), original bill of sale, etc in order to have the tarjeta de circulacion issued in your name. An FMT and money can buy a car, but you’ll be staring at it on la calle if you can’t get it registered.
  2. You’ll need to pay taxes on the purchase of the car plus an annual tax to drive it.
  3. It’s gotta conform to EPA emissions standards and requirements. If it’s not already certified, the car must be imported, modified, tested, and certified by an Independent Commercial Importer. This is the part that’ll hold you up. The Tsuru doesn’t meet required US safety requirements- no airbags, no side impact beams, and no passive restraints; no way, Jose!
  4. If you get far enough or want to invest in modifications to make it legal, pay the fees to get it on US soil- tariff, bond and surety fee, customs fee, processing fee, and the “you’ll never get this thing titled” fee…

Buy someone’s rust-free US version B13 and install a set of Tsuru headlights – at least they’ll have intermittent wipers. Mexican Tsurus are a base model car- 1.6L, 13” steelies, rear drum brakes, all things that don’t compensate for the effort needed to import a car to the US.  

mexican cop tsuru
Tsurus are found all over Mexico, from taxis to cop cars.


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