Advice for M&M - Automotive Edition

 It has been a while since I have offered any advice for the youngling. Who, by the way, is now officially a teenager. I suppose that means I have to retire the Cutest Little Girl in the World moniker and come up with something more age appropriate. She claims 90% of her personality comes from me. So, it’ll probably be something inappropriate. 

Without further ado, I present some accumulated automotive wisdom. 

1) The gas gauge lies. Consider it a reasonable facsimile of an estimate at best. Most gas gauge’s rely on a small plastic float attached to a thin metal wire lever which, in turn, is attached to a sensor that hopefully some college educated idiot calibrated correctly before turning the design over to a factory in China where someone whose name may or may not sound like loose change landing on cookware might or might not know how to assemble Part A into Slot B correctly such that a functional part results. 

Corollary: fuel flow meters are marginally more accurate, but it’s a garbage in garbage out system if the computer programmer coding the ECM can’t tell the difference between his/her/their nostril and fourth point of contact. For instance, the fuel flow meter on my truck’s information center is off by 1.2 to 1.5 gallons used per tank. So, if it says you’ve used 30 gallons, you’re really at about 31.5 gallons gone and fumes will only get you so far. 

2) Allow me to explain a concept important to pilots and people on a long cross country road trip in a 3/4 ton pickup: Usable Fuel. According to Ford, my truck has a 35 gallon tank. Now, depending on the phase of the moon, the slope of the gas station pump lot, the angle the truck is parked, atmospheric pressure, and whether or not you have pissed off God in an amusing way, you MIGHT only be able to put 34 gallons in or you could get lucky and squeeze 35.5 gallons down to pipe. The truth is you never REALLY know how much gas you have in the tank. 

Now, on with our explanation. From our nebulous starting point of a “full tank of gas”, you can’t use the entire theoretical amount of gas in the tank. What? The hell you say! T’is true. There are several factors conspiring to prevent you from using every drop and fume of gas in your tank. For instance, tank baffles and ribs and other obstructions. Your tank doesn’t have a flat bottom. There are, in fact, ridges and things to keep your gas from sloshing around too much and keeping your from starving out the fuel when you have to panic stop because you dropped your donut into you coffee while putting on makeup and watching Tik Tok. 

With that in mind, there is a point at which the “sock” attached to the bottom of your fuel pump can no longer reach and absorb fuel remaining in the tank. When that happens, the go juice no go to the fuel lines connected to the carb(s)/injectors and makey no fire to push the pistons that makes the magical horsepower and torque that flogs the wheels to merry go round. Eventually, your momentum runs out and you get to meet your local roadside assistance person. Not. Happy. Making.

Another corollary: manufacturers have been know to lie about capacities too. I had a Nissan Maxima once that claimed to have a 25 gallon gas tank. More than once, it took 27 gallons to fill it after a certain red head drove it.

3) Not all parts are created equal. If you want to be absolutely sure a part SHOULD/WILL work in your car, buy the branded part. Motorcraft for Fords, MOPAR for Dodge/Chrysler, etc. That isn’t to say that the factory branded parts are the BEST parts, but they are the parts that the factory used to build the vehicle as designed.

 Now, here is where it gets kinda hinky and weird. Ford doesn’t make all the parts for their cars and trucks. That’s outsourced to private label manufacturers who may also sell similar / identical parts under their own brand or someone else’s. So, if you buy a Motorcraft spark plug, it may have actually been made by Denso or Autolite or someone else to Ford’s specs and put in a pretty box that says “Motorcraft” on the outside. But the people that made that plug don’t cash FoMoCo paychecks at the end of the month. There are people who will swear on their dying breath that the off branded plug made on the same line to the same specs doesn’t work in their vehicle.

 Maybe. Maybe not. 

My truck just got a new set (all 16 of ‘em) of NGK Iridium plugs. These are plugs that are supposed to be better than factory platinum plugs, but I keep getting weird misfire codes  I’ve swapped coils, removed plugs, checked gap, reinstalled, made sure everything is securely connected, etc. And  yet, if you look at it funny, it shows intermittent misfire codes. My cousin the mechanic turned engineer tells me “Yeah, NGKs don’t do well in domestic vehicles.” 

Son…of….a…. Do you know how much those SOBs cost?

4) where to buy parts? In the grand hierarchy of cost to benefit, the dealer will be the best place to buy parts but also the most expensive. At the other end of the spectrum is a junkyard sourced part from the same vehicle (“it ran when crashed”). So, what do I suggest in the between space. In my opinion, eBay is the parts supplier of last resort. I’d rather have a junkyard part over an eBay part of questionable quality and origin. Been there. Done that. For brick and mortar stores, I’ve had equal luck/success with Autozone, O’Reilly’s and Advanced Auto. Price wise, they are all in roughly the same ballpark. Ditto for quality. Autozone has an asterisk by them as they saved me from being stranded in a small town on July 4TH many years ago. For online parts stores, Rockauto is my first choice and Amazon as a distant second. I’ve not personally used any of the other online parts houses. So, I will cast no shade where I’ve not been.

5) All vehicles are compromises. Comfort, speed and power are just a question of how much money you want to spend. Generally speaking, as horsepower, torque and speed increase, gas mileage, longevity and reliability decrease. Need proof? Go watch any high performance racing event. NHRA drag racing is a prime example. It’s pretty common to see at least one if not more 10,000 horsepower, nitro methane, supercharged V8 grenade in spectacular fashion over the course of a weekend. And they do a complete tear down and rebuild in between each 1/4 mile run. Unless you pull a heavy trailer or have other special needs, a naturally aspirated V6 makes all the power and speed most people need. You don’t need a 600 horsepower, twin turbo V12 in your daily driver grocery getter. 

6) Like the signs at the shop says: Repairs can be good, fast or cheap. Pick any two. If you want it cheap and fast, it won’t be good. If you want it good and fast, it won’t be cheap. If you want it good and cheap, it won’t be fast. Choose wisely.