Engine Internals & Performance Tuning
SAE Certified Horsepower Meaning: Claimed vs Measured
SAE certified horsepower meaning, explained: what J1349 and J2723 require, why two sites show different figures, and how to find your engine's rating.
Latest
Spec Lookup
Mid Year Model Change Car Specs: How to Tell Yours
Mid year model change car specs explained: why makers change parts and figures partway through a year, and how to tell which version you have.
Fluids, Refrigerant & Chemicals
What Refrigerant Does My Car Use? Check the Label
Your vehicle states it on a label under the hood. A chart cannot answer this reliably: the transition happened at different points for different cars.
Spec Lookup
Same Car Different Specs by Country: Does Yours Apply?
Same car different specs by country? Why US, Canadian, European and JDM versions differ, and how to confirm a figure fits your car.
Spec Lookup
Are Car Spec Websites Accurate? Where the Data Comes From
Are car spec websites accurate? See where aggregator data comes from, which figures hold up, and how to check a number before you rely on it.
Fluids, Refrigerant & Chemicals
Can I Use ATF for Power Steering? Sometimes. Not Always.
The internet is right about some vehicles and wrong about others. Seal compatibility is the mechanism, and the failure is delayed rather than immediate.
Part Numbers
Call Dealer for Part Number: When It Beats Searching
Know when to call dealer for part number help, what to have ready and what to ask, so you get the right OEM number for your VIN on the first call.
Spec Lookup
Can I Trust AI for Car Specs? When to Check the Manual
Can I trust AI for car specs? Learn why chatbot figures go wrong, which uses are safe, and how to verify a torque or fluid spec before you use it.
Fluids, Refrigerant & Chemicals
GL-4 vs GL-5 Gear Oil: Higher Is Not Better Here
The numbers describe different applications, not better and worse. In the wrong application the additive package is the problem rather than the benefit.
Spec Lookup
Verified Car Spec Source: What It Means Here
What makes a verified car spec source, the four checks a number must pass here, and the figures we refuse to print so you never torque to a guess.
Fluids, Refrigerant & Chemicals
CVT Fluid: Why Universal Is Usually Wrong Here
A CVT transmits torque through friction at a belt or chain contact, so the fluid's friction behavior is part of how the transmission works, not incidental.
Fluids, Refrigerant & Chemicals
What ATF Does My Car Take? Coverage vs Licence
A bottle listing 40 vehicles is making a coverage claim. A licensed specification is a different kind of statement, and only one of them is checkable.