Today I was thinking about how many liters of fuel are burned by the millions of cars on our planet.

I think it's must be a lot of fuel that's burned every day.

I asked gsearched on Google , "how many of vehicles are there isn the world?"

And gGoogle told me that the world has 1.47 billion of vehicles.

MIn my opinion, these vehicles burn a lot of fuel because if half of these vehicle makes are driven 100 kilometers ofa day and the average fuel consumption is 7 liters onper 100 kilometers, then they burn more than 5 billion liters a day.

It is more then 5 billion of liters in day .

I think combining this sentence with the previous one makes it sound more natural.

It is a huge amount of fuel.

Today, I was thinking about how many liters of fuel are burned by the millions of cars on our planet.

I think it's a lot of fuel every day.

I asked google how many of vehicle isthere are in the world?.

"many [pleural noun] are" is the phrase to memorize. "many" is used for countable objects so the noun is always pleural.

question mark -> period: The fact that you asked google is not a question, but a fact. However, "I asked google 'how many vehicles are there in the world?'" would be fine, but the quotes are necessary. Technically, there's an implied period after the question mark because, again, the fact you asked google is still an affirmative statement. Also, note that in question form, "there are" becomes "are there". I can't explain the technical reasons, though.

And google told me that the world has 1.47 billion of vehicles.

This would actually be more natural as one sentence:

> I asked Google "How many vehicles are there in the world?" and it told me there were 1.47 billion vehicles.

This time, the punctuation implied after the question mark is a comma.

My opinBy my estimation, these vehicle burn a lot of fuel because if half of these vehicle make 100 kilometers of day and average fuel consumption is 7 liters on 100 kilometers (then) that is more then 5 billion of liters in day .

In my opinion, winter is cold--"in my opinion" is used to express subjective opinions or soften judgments, not appear too authoritative. However, calculations or estimations are not opinions.

(then?): "if" specifies a condition, "and" adds to that condition, the conclusion must follow in the same sentence. "If the weather allows, (then) I will go to the park." I moved the next sentence into this one for that reason.

it -> that: It's hard to describe when to use which, but "that" feels more correct to me here.

It is more then 5 billion of liters in day .

Today I was thinking about how many liters of fuel are burned by millions of cars on our planet.

I might add each day. Sounds a bit more balanced.

I would think it' is a lot of fuel every day.

The information was given previously, so it doesn't matter that much, unless you are writing something formal.

I asked google how many of vehicles are isn the world?

And google told me that the world has 1.47 billion of vehicles.

My opinionI was formulating, these vehicles burn a lot of fuel, because if half of these vehicle makes travel 100 kilometers ofeach day and the average fuel consumption is 7 liters onper 100 kilometers.

IThat is more then 5 billion of liters ina day .

IThat is a huge amount of fuel.