Spec Lookup - AutoChartGuide (Page 6)

Tire speed rating guide showing a Y-rated tire, speed rating chart, and the safety risks of choosing a lower speed rating

Tire-Wheel

Tire Speed Rating Explained: What Downgrading Costs

The speed rating certifies more than top speed. It is a proxy for construction and heat tolerance, which is why 'I drive slowly' is not the whole argument.

Tire guide comparing load range, load index, and ply rating, showing the differences between tire strength class, weight capacity code, and construction rating

Tire-Wheel

Load Range vs Load Index vs Ply Rating: Three Systems

One tire can carry an E, a 121 and a 10-ply marking. They are three systems from three eras, and you cannot convert between them by reasoning.

ire load index 95 highlighted on a tire sidewall with a comparison of lower and higher load capacity ratings

Tire-Wheel

Tire Load Index Explained: Why Lower Is Never Free

The load index is an index into a standard table, not a weight, and the scale is not linear. Here is what it rates and why going lower is never neutral.

Compare LT vs P tires to understand how the service type letter affects strength, load capacity, comfort, durability, and everyday driving.

Tire-Wheel

LT vs P Tires: What the Service Type Letter Changes

P, LT, ST and XL are not quality grades. They describe service type and rating conventions, and swapping between them changes how the tire is rated.

P215/65R17 tire size explained with labels for passenger tire type, width, aspect ratio, radial construction, and 17-inch rim diameter

Tire-Wheel

Tire Size Numbers Meaning: P215/65R17 Explained

Three numbers in three different unit systems. Here is which is millimeters, which is a percentage, which is inches, and why that trips people up.

Tire sidewall guide showing how to read tire size, load index, speed rating, DOT code, and other sidewall markings

Tire-Wheel

How to Read a Tire Sidewall: Every Marking Decoded

A sidewall carries about six independent specifications plus manufacturing data. Here is what each marking governs, in the order you meet it.

Missing door jamb sticker on a car door frame with guidance on how to verify vehicle information using official sources

Find Your Numbers

Door Jamb Sticker Missing? What to Do (Not Order One)

A reproduction label carries no authority. Recover the information first from the manual, the manufacturer and a dealer, then decide about a replacement.

Car trim identification guide showing badges, VIN lookup, door-jamb label, and vehicle information used to verify the correct trim level

Find Your Numbers

How to Tell What Trim Your Car Is (Badges Lie)

A badge is the weakest evidence on the car. Here is the evidence hierarchy for verifying trim, and why trim decides which part or spec applies to you.

VIN recall check guide showing a car VIN lookup, recall results dashboard, and key limitations of checking recalls by VIN for free

Find Your Numbers

How to Check Recalls by VIN (Free, and What It Misses)

The official US recall check is free and takes a VIN. How to run it, why it misses service bulletins, and what a recall obliges the manufacturer to do.

Two websites showing different vehicle specifications for the same car, highlighting data mismatches and the need to verify sources

Find Your Numbers

Why Two Websites Give Your Car Two Different Numbers

Five structural reasons published car specs disagree, and a ranking system for deciding which of the sources in front of you to believe.

Model year and build date comparison showing a vehicle door-jamb label, manufacturing date, and model year differences

Find Your Numbers

Model Year vs Build Date: Why Your Car Won't Match the Chart

Model year is a designation. Build date is a fact. Here is where each is recorded on your vehicle and why parts catalogues care about the second one.

Engine code guide showing three sources to verify the correct engine code, including the emissions label, VIN, and service manual

Find Your Numbers

How to Find Your Engine Code: Three Sources That Should Agree

Your VIN, the under-hood label and the engine itself each identify the engine. Here is how to read all three, and what it means when they disagree.