El kilometraje aparece en el odómetro.

Because kilometraje is a masculine noun in Spanish, so it takes el.

A useful pattern: many nouns ending in -aje are masculine, for example:

• el viaje
• el garaje
• el paisaje
• el kilometraje

So el kilometraje is the normal form.

Aparece is the third-person singular present tense of aparecer.

So it matches the singular subject el kilometraje.

Conjugation idea:

• yo aparezco
• tú apareces
• él/ella/usted aparece

In this sentence, aparece can mean something like:

• appears
• shows up
• is displayed

In everyday Spanish, it often works naturally for information that appears on a screen, panel, or device.

Because aparece gives the idea that the mileage shows up / is displayed on the odometer.

Compare:

• El kilometraje aparece en el odómetro.
  = The mileage appears / is displayed on the odometer.

• El kilometraje está en el odómetro.
  = The mileage is on the odometer.
  This is understandable, but it sounds more like location than display.

• El kilometraje es en el odómetro.
  This is not natural here.

So aparece is a good choice when talking about what a device or display shows.

En is the normal preposition for saying something is in, on, or inside a place/device, depending on context.

So:

• en el odómetro = on the odometer / in the odometer display

Spanish often uses en where English might use either in or on.

Other examples:

• Aparece en la pantalla. = It appears on the screen.
• Está en el tablero. = It is on the dashboard.

So en is completely natural here.

Because odómetro is a masculine noun, so it takes el.

This also follows a common pattern: nouns ending in -o are often masculine.

• el odómetro
• el carro
• el motor

Also, the article el here sounds natural because we are talking about the odometer of a specific vehicle or the odometer in general as the relevant instrument.

The accent mark shows where the stress goes: o-DÓ-me-tro.

Without the accent mark, standard Spanish stress rules would place the stress differently, so the written accent is necessary.

Pronunciation help:

• odómetro → o-DO-me-tro, with the stress on dó
• kilometraje → ki-lo-me-TRA-he, with the stress on tra

Also remember that the j in kilometraje has the Spanish h-like sound found in many Latin American accents.

Not always in practice.

Literally, kilometraje is related to kilometers, and it often refers to:

• total distance traveled
• mileage reading
• distance accumulation on a vehicle

Even if a learner thinks in terms of English mileage, Spanish may still use kilometraje as the standard word.

In some places or contexts involving miles, you may also hear:

• millaje

But kilometraje is very common and widely understood across Latin America.

Because the subject is el kilometraje, which is singular.

Even though mileage refers to an amount or measurement, grammatically it is treated as one singular thing.

So:

• El kilometraje aparece... ✔
• El kilometraje aparecen... ✘

The verb must agree with the grammatical subject, not with the idea of “many kilometers.”

Yes. Spanish word order is flexible.

The most neutral order is:

• El kilometraje aparece en el odómetro.

But you could also say:

• En el odómetro aparece el kilometraje.

That version puts more attention on where it appears.

Both are grammatical, but the original sentence is the most straightforward and neutral for everyday use.

Yes, in some contexts, but the nuance is a little different.

• El kilometraje aparece en el odómetro.
  = The mileage appears / is displayed on the odometer.

• El kilometraje se ve en el odómetro.
  = The mileage can be seen on the odometer.

Se ve focuses more on visibility, while aparece focuses more on what the instrument shows.

Both can work, but aparece is a bit more direct for device display language.

No.

• odómetro = odometer
  Measures total distance traveled.

• velocímetro = speedometer
  Shows current speed.

This matters because English speakers sometimes confuse the two dashboard terms.

So in this sentence, odómetro is the correct word if you are talking about total mileage/distance.

A broad Latin American-style pronunciation guide could be:

El kilometraje aparece en el odómetro.

Approximate pronunciation:

el ki-lo-me-TRA-he a-pa-RE-se en el o-DÓ-me-tro

A few helpful notes:

• j in kilometraje sounds like a strong English h
• c in aparece before e sounds like s in Latin America
• r in aparece is a tapped Spanish r
• stress falls on:
  • -tra- in kilometraje
  • -re- in aparece
  • -dó- in odómetro

Yes, it is grammatical and natural, especially in instructional, technical, or explanatory contexts.

For example, it would fit well in:

• a manual
• a vehicle description
• a dashboard explanation
• a language-learning example

In everyday conversation, a speaker might also say things like:

• El kilometraje se muestra en el odómetro.
• El odómetro muestra el kilometraje.

Those may sound slightly more explicit, but your original sentence is perfectly good Spanish.