Regular gas in G37??

[t-bone1924]

I was wondering whether the use of regular gas in the new G37 would be detrimental to the engine. I know that all of the literature that I have seen say "premium fuel required".

Other cars I have driven say premium fuel recommended, but the only thing that happens is a little less power and worse mileage.

Anyone know for sure? I don't need opinions, just the facts, if you really know them!

[Rex]

I was wondering whether the use of regular gas in the new G37 would be detrimental to the engine. I know that all of the literature that I have seen say "premium fuel required".

Other cars I have driven say premium fuel recommended, but the only thing that happens is a little less power and worse mileage.

Anyone know for sure? I don't need opinions, just the facts, if you really know them!

From one of NICO's technical experts

The main factor to consider is the amount of amine detergents in regular vs premium...............as buying these detergents [techron, BG44k, etc] standalone will cost significantly more than paying the 20 cents per gallon premium to get them already blended into gasoline.

So called top tier just add the absolute legal minimum not enough to really clean things.

If you must alternate fill ups between reg and premium or use midgrade.

In hot summers or mountains you may notice differences in octane.

[t-bone1924]

Okay, from what your expert says, am I to understand that the issue in using regular vs. premium is mainly based on cleaning additives and not on octane level?

I asked my question from the standpoint of the new VVEL action; revs being regulated by the intake valves, etc.

[SeismicGuy]

This subject always cracks me up, especially when it comes from someone who has opted to obtain a performance car. Just do the math and see if your concerns are warranted. Assuming 30 cents more a gallon for premium (probably not really that much) and assuming you drive 10,000 miles a year and get 20 mpg, that comes to 500 gallons of gas. So 500 gallons at 30 cents more per gallon comes to $150. Do you really want to downgrade the potential performance of you car so that you can save $150 per year?

Doug

[Rex]

Okay, from what your expert says, am I to understand that the issue in using regular vs. premium is mainly based on cleaning additives and not on octane level?

I asked my question from the standpoint of the new VVEL action; revs being regulated by the intake valves, etc.

The long and short of it, is the octane effects the combustion chamber and how clean it burns (residue/sediment left behind). The lower octane will leave more behind and has less to clean the pre-combustion chamber parts of the fuel system.

I know you don't want opinions, but if you're worried about something that's as little <$5.00 per fill-up, you've probably bought the wrong car.

On the other hand, if you're not going to own the car past the warranty period and aren't worried about the dealer/manufacturer claiming the damages were from improper use/maintenance, put whatever you want in it. Just keep in mind the $5.00 you save this week/month may cost you $100's even $1000's 2 years from now.

[mikek]

engines have knock sensors that detect detonation and automatically retard the spark to compensate. The delay means maximum gas expansion occurs when the piston is farther along in its down stroke and thus there's more room in the cylinder head. This reduces peak cylinder pressure, eliminating knock but also giving you less power and poorer mileage.All to save three bucks per tankful using regular instead of premium as specified.

Others say premium is purer or contains detergents that will cleanse your engine of deposits. government regulations require detergents in all grades of gasoline.

[t-bone1924]

Thanks for the responses. If the G requires it, premium it will get!

Saving money was not the main issue for my question--wasting money was. I have owned several other high performance cars, all of which were far more expensive than the G37, which called for premium fuel. In all cases, regular did the job just fine albeit a little less mileage per tank, mainly because the computer adjusted for the lower octane.

[Rex]

... Saving money was not the main issue for my question--wasting money was. ...

And that's a great point. But what a lot of people don't think about (or aren't worried about) is "wasting" a few dollars per tank now saves (potentially) a lot in the future if you plan on driving the car past 100k.

Too few people do today, and those that do, aren't worried about the possible costs/repairs at that time. They think Today, not Tomorrow. Not saying you fall into that category.

[Q45tech]

The problem is the government MINIMAL STANDARDS for detergents..........they are not high enough to for high compression performance cars they are just enough for average cars driven sedately. to do otherwise would be a waste of chemicals [expense].

Another few pennies per gallon would make Premium really Premium.

Simple test: use a can BG44K injector/valve/piston crown cleaner in your tank, if you notice the/any positive difference you have proved the gasoline you have been buying is inferior for your particular engine!

A simple $15 test will let you know.

If your driving is worst case : cold start driving less than 15 miles then repeat, then repeat without an hour per day on highway at 55 mph, government standard gasoline WILL degrade your internals with deposits after 3,000 miles 90 days or less.

[Kendahl]

If you already have a G37, read your owner's manual. If not, read the pdf file that you can download from Infiniti's web site. According to the latter, the engine in the G37 (VQ37VHR) requires 91 octane unleaded premium. If premium is unavailable, you can put in 87 octane regular. However, you should put in no more than necessary, drive gently on the mixture, and fill up all the way with premium as soon as possible.

A mixture of premium and regular will have an octane rating somewhere between 91 and 87. The greater the percentage of regular, the lower the octane of the mixture. The G37's engine can use gasoline with up to 10% ethanol as long as octane requirements are met. E-10 is usally 89 octane. If you can't get premium, I think it would be better to add E-10 than regular.

[IBJanky]

I'd just put in whatever the manufacturer recommends

[Q45tech]

When you read the details, you see E10 is tolerated for the period of the warranty or at least they will repair any failure damage. but what happens years later after the warranty...........there are no comments about this.

The less ethanol/water the better for longevity.

The EPA, Government, Labor unions, and manufacturers are very very unhappy that the average car on the road is now 9 years old [38% are 11 years or older].Ethanol was created to help rectify this and add jobs.