Learn Hardcore French: Cette voiture consomme beaucoup de carburant.

Memorize une voiture (a car) and la voiture (the car).
The presence of cette (feminine demonstrative) and la / une (feminine articles) is what shows you that voiture is feminine.

Many nouns ending in -ure are feminine (like voiture, culture, nourriture, facture), but treat that as a tendency, not an absolute rule.

How would the sentence change if I talk about several cars?

You must change both the demonstrative and the verb to the plural:

Singular: Cette voiture consomme beaucoup de carburant.
This car uses a lot of fuel.
Plural: Ces voitures consomment beaucoup de carburant.
These cars use a lot of fuel.

Changes:

cette → ces
consomme → consomment (3rd person singular → 3rd person plural)

What exactly does consomme mean here? Is it like English consume or use?

The verb consommer literally means to consume, but in everyday French, in this context, it corresponds closely to English to use (in the sense of fuel, energy, resources).

Cette voiture consomme beaucoup de carburant.
≈ This car uses/consumes a lot of fuel.

You would not normally say Cette voiture utilise beaucoup de carburant. It is understandable, but utiliser is less idiomatic for fuel consumption; consommer is the standard verb for:

fuel: consommer du carburant
energy: consommer de l’électricité
food: consommer des produits frais (to consume / eat)

Does the French present tense consomme mean “is using” or “uses”?

The French simple present can cover both meanings:

Cette voiture consomme beaucoup de carburant.
- This car uses a lot of fuel. (habitual/general fact)
- This car is using a lot of fuel. (right now / at the moment)

French usually does not distinguish between uses and is using in form. Context normally clarifies which sense is intended.

Why is it beaucoup de carburant and not beaucoup du carburant or beaucoup des carburants?

With expressions of quantity like beaucoup, French uses de (or d’ before a vowel sound) directly before the noun, without any article:

beaucoup de carburant = a lot of fuel
peu de temps = little time
assez de sucre = enough sugar

So you say:

beaucoup de carburant (correct)
beaucoup du carburant (generally incorrect here)
beaucoup des carburants (only in very specific contexts, like “many of the fuels that we studied…” — you are referring to a specific, limited set)

For a general quantity, always use beaucoup de + noun.

Why is it de carburant and not de le carburant?

After beaucoup, you must use the bare de, never de le / de la / des:

beaucoup de carburant (correct)
beaucoup du carburant (wrong for a general statement)

du / de la / des are partitive articles (roughly “some”), but they disappear after expressions of quantity:

du carburant = some fuel
beaucoup de carburant = a lot of fuel
trop de carburant = too much fuel
un peu de carburant = a little fuel

What is the difference between carburant and essence?

carburant is a general word for fuel (for engines). It can refer to petrol, diesel, aviation fuel, etc.
essence usually means gasoline / petrol specifically (for most cars).

So:

Cette voiture consomme beaucoup de carburant.
This car uses a lot of fuel. (general)
Cette voiture consomme beaucoup d’essence.
This car uses a lot of petrol/gas. (more specific to gasoline)

Both are correct, but carburant is more general and a bit more technical; essence is very common in everyday speech when talking about standard petrol cars.

Is carburant countable in French? Can I say des carburants?

In this sentence, carburant is a mass noun (uncountable), like water or fuel in English:

beaucoup de carburant = a lot of fuel

However, carburant can be plural in technical or scientific contexts when referring to different types of fuels:

On étudie différents carburants alternatifs.
We are studying different alternative fuels.

For ordinary speech about how much fuel a car uses, you keep it singular as a mass noun.

How is Cette voiture consomme beaucoup de carburant pronounced?

Approximate IPA pronunciation (standard French):

Cette voiture consomme beaucoup de carburant
/sɛt vwa.tyʁ kɔ̃.sɔm bo.ku də kaʁ.by.ʁɑ̃/

Notes:

cette: /sɛt/
voiture: /vwa.tyʁ/
consomme: /kɔ̃.sɔm/ (nasal on sound in con-)
beaucoup: /bo.ku/ (final p is silent)
carburant: /kaʁ.by.ʁɑ̃/ (final t is silent; nasal an sound)

There is no required liaison between beaucoup and de in this expression.

Can I change the word order, like Cette voiture beaucoup de carburant consomme?

No, that word order is incorrect in standard French.

The normal pattern is:

Subject + Verb + Object
Cette voiture (subject) consomme (verb) beaucoup de carburant (object).

In neutral statements, you cannot move beaucoup de carburant in front of consomme without adding special structures. Cette voiture consomme beaucoup de carburant is the natural order.

How do I make this sentence negative?

Use ne … pas around the verb:

Cette voiture ne consomme pas beaucoup de carburant.
This car does not use a lot of fuel.

Structure:

ne
- consomme
  - pas

In spoken French, ne is often dropped:

Cette voiture consomme pas beaucoup de carburant. (very common orally, but informal in writing)

How would I say it in the past and in the future?

Two common options:

Past (passé composé):

Cette voiture a consommé beaucoup de carburant.
This car used / has used a lot of fuel.

Future (futur simple):

Cette voiture consommera beaucoup de carburant.
This car will use a lot of fuel.

The basic structure stays the same; only the verb form changes.