Premium vs Regular gas - Altima/Maxima

I thought that the V6 Altima was the same engine as all of Nissan’s Maximas. Yet Altima drink regular and Maxima guzzle premium. What am I missing?

The weight of the vehicle…and the tranny gearing…and the size of the tires…

If the Maxima “requires” premium then you must use premium. If it is merely “recommended” then use regular. The Maxima is a higher end vehicle so the engines probably have higher end parts. The fact that they have the same size engine in cubic inches means very little as far as their relationship to each other.

When I compared specs, the Maxima engine shows a 10.6:1 compression ratio and 290 hp, while the Altima is listed at 10.3:1 and 270 hp. So the engines aren’t the same, after all…but I would carefully read the Maxima manual, is premium ‘required’ or ‘recommended’?

They both have basically the same engine, but they apparently have different cumbustion chamber designs. The Maxima’s higher compression needs premium fuel to get that extra 20 HP. The owners manual would say if it is necessary for the longevity of the engine or not.

Typically the 3.5L VQ V6 is one of the most octane sensitive engines around. And at least up until 2005, 91 octane was recommended if you wanted to get the advertised amount of power and fuel economy you paid for. I’ve noticed that they’ve squeezed some more power out of it since then. I would wager that the Maxima has a revised version of the engine. But if you look at page 456 of the 2010 Maxima’s owners manual as seen here

We can see that 87 octane is allowed, but the owner may experience diminished performance

Man-oh-man - 456 PAGES - is it any wonder that folks don’t read their owner’s manuals? That a telephone book!

Thanks everyone, that was quick!
I just did the math and if I drive 15,000 miles the total savings for the YEAR would be roughly $272.00.
Does not sound like too much for a $30,000 car.
The manual does say that 87 octane is acceptable.
Thanks again this was very helpful to me.

Along with the loss in power comes a loss in fuel economy as well. In some cases there’s no real saving as all.

FoDaddy makes a good point.

For example, if premium costs 5% more than regular gas, but your mileage drops 5% with regular (like from 21 to 20 mpg), then it’s not costing you anything more to fill up with premium.