Fluids, Refrigerant & Chemicals

Refrigerant Charge Weight: Why Topping Off Fails

Your A/C charge is a weight printed on the vehicle's own label, not a pressure you can feel. Why a can gauge cannot tell you, and what low really means.

Dipstick oil color chart infographic: amber, brown, black and milky oil meanings

Fluids, Refrigerant & Chemicals

Dipstick Engine Oil Color Chart 2026: What Each Means

What each engine oil color on the dipstick means, according to the oil companies, and where they disagree.

Car A/C refrigerant label showing R-134a and examples of R-1234yf and R-744 refrigerant types

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.

ATF and power steering fluid comparison showing when ATF may or may not be suitable

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.

GL-4 vs GL-5 gear oil comparison showing the differences between the two gear oil specifications

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.

CVT fluid guide showing why universal CVT fluid is often the wrong choice

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.

ATF transmission fluid comparison showing multi-vehicle coverage, OEM licence, and owner’s manual specifications

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.

DOT 3, DOT 4, and DOT 5 brake fluid comparison showing different formulas and compatibility warnings

Fluids, Refrigerant & Chemicals

DOT 3 vs DOT 4 vs DOT 5: The Numbers Are Not a Ladder

DOT 5 is silicone based and not compatible with the glycol fluids either side of it. DOT 5.1 is glycol based despite the number. That is the whole trap.

OAT, HOAT, and IAT coolant types compared with warnings about mixing incompatible coolants

Fluids, Refrigerant & Chemicals

Can You Mix Coolant Types? What OAT, HOAT and IAT Do

It depends on what and how much, and that cannot be judged from a description. Here is what the chemistries are and why the damage is slow and quiet.

Coolant color guide showing why coolant color alone is not the correct specification

Fluids, Refrigerant & Chemicals

Coolant Color Is Not a Spec: Reading the Actual One

Dye is not chemistry. The same color has covered different chemistries and the same chemistry has come in different colors. Here is what to read instead.

Oil capacity vs dipstick comparison showing owner’s manual oil spec and dipstick oil level reading

Fluids, Refrigerant & Chemicals

Oil Capacity vs Dipstick: Which One Is Actually Right?

A published capacity is an estimate for a nominal condition. The dipstick measures the engine in front of you, and the dipstick wins every time.

Full synthetic vs synthetic blend motor oil comparison highlighting label differences and regulation concerns

Fluids, Refrigerant & Chemicals

Full Synthetic vs Blend: Is the Label Even Regulated?

The words on the front of the bottle are far looser than buyers assume. The marks on the back are the part you can actually verify.