Con tan poca gasolina, paramos en una gasolinera que está cerca del puente.

In Spanish, con can introduce a circumstance or condition, not just physical accompaniment.

So con tan poca gasolina literally is with so little gas, but in context it means:

• given that we had so little gas
• because we only had a little gas left
• with so little gas, ...

It sets the scene for why the action happened: paramos.

Both are possible, but they are not exactly the same.

• muy poca gasolina = very little gas
• tan poca gasolina = so little gas

Tan often adds stronger emphasis and can suggest a consequence or result. In this sentence, that works well because the low amount of gas leads to stopping at a petrol station.

So con tan poca gasolina feels very natural for:

• with so little gas, we stopped...

Because gasolina is a feminine singular noun.

Poco/a/os/as agrees with the noun it describes:

• poca gasolina — little gas
• poco tiempo — little time
• pocas opciones — few options
• pocos coches — few cars

So here:

• gasolina = feminine singular
• therefore poca

Because gasolina is being used as an uncountable substance, in a general sense.

Spanish often omits the article with mass nouns when talking about an amount of something:

• poca gasolina = little gas
• mucha agua = a lot of water
• demasiado dinero = too much money

If you added an article, it would usually sound more specific:

• la gasolina = the gasoline / gas

But here the sentence is just talking about the amount available, so poca gasolina is the natural form.

In this sentence, paramos is most naturally understood as the preterite:

• paramos = we stopped

That said, paramos can also be the present tense form of nosotros:

• paramos = we stop

So the form itself is ambiguous. Context tells you which meaning is intended. In a sentence like this, with a completed action in a narrative, Spanish speakers will usually understand it as preterite.

This is a common feature of some -ar verbs in Spanish: the nosotros present and nosotros preterite forms can look identical.

Because the verb parar is commonly used with en to mean stop at a place.

• paramos en una gasolinera = we stopped at a petrol station

Spanish does not structure this like go to. Even though there is movement before the stop, the important idea is the location where the stopping happens.

Compare:

• ir a una gasolinera = to go to a petrol station
• parar en una gasolinera = to stop at a petrol station

So en is the normal preposition here.

Que is a relative pronoun here. It introduces extra information about una gasolinera.

So:

• una gasolinera = a petrol station
• que está cerca del puente = that is near the bridge

Together:

• una gasolinera que está cerca del puente = a petrol station that is near the bridge

In English, that is sometimes optional:

• a petrol station (that) is near the bridge

In Spanish, que is normally required here.

Because estar is used for location.

• está cerca del puente = it is near the bridge

Spanish normally uses estar for where someone or something is located:

• Madrid está en España
• La gasolinera está cerca del puente

Using ser here would be incorrect.

Because del is the contraction of de + el.

• cerca de = near
• el puente = the bridge

So:

• cerca de el puente → cerca del puente

This contraction is mandatory in normal Spanish.

A useful thing to remember:

• de + el = del
• a + el = al

Because when cerca is followed by a noun, it normally needs de.

So:

• cerca del puente = near the bridge
• cerca de casa = near home
• cerca de la estación = near the station

You can use cerca on its own only when the reference is already clear:

• Está cerca = It is nearby

But once you name what it is near, you need de.

They are related words, but they mean different things:

• gasolina = petrol / gas
• gasolinera = petrol station / gas station

So in the sentence:

• Con tan poca gasolina = With so little gas
• paramos en una gasolinera = we stopped at a gas station

This is a very useful pair to remember because learners often mix them up.

Yes. A few natural alternatives are:

• Como teníamos tan poca gasolina, paramos en una gasolinera cerca del puente.
• Al tener tan poca gasolina, paramos en una gasolinera que estaba cerca del puente.
• Con tan poca gasolina, tuvimos que parar en una gasolinera cerca del puente.

These all keep the same basic meaning, but the original sentence is perfectly natural. It is especially good for expressing the situation first, then the action.