I live in NJ and we're not allowed to pump our own gas. When I got home tonight I looked at my gas receipt and I noticed that the NIMROD pumped 16 gallons of regular fuel into my Z. How much damage will this cause ? How much trouble am I in ?

 

You might get some pre-ignition knock as the load on the engine increases (when you accelerate.) It will be annoying but shouldn't do any damage from this one tank. When you get to half a tank, fill up with premium, then do it again at the next half tank.

 

Drive around awhile and listen for knoking noises from the engine. If you have this, head to AutoZone and pick up some octane booster. If no knocking, then you are fine. The computer in the Z should sense the presence of the regular fuel and retard the timing so that it will not knock and cause damage. You will loose some power in this tank of gas, but in a week or so you will have the premium back in, so no worries. Also, when you get down to about a half tank, top off with premium to raise the octane level of what is in your tank, that should help as well.

 

This is interesting to know the answer, but unfortunately I don't know. I have two other cars that call for premium. If you use less than 91 octane in the Volvo the check engine light will come on. In my Chrysler, the engine management system will adjust timing and spark to adjust to the lower octane. Hopefully you will only realize less pep until you use up all the gas. I don't know if you should use an octane booster to compensate.

 

Only when an engine knock really badly will you hear it.

Ignition will be retarded when the knock sensor senses preignition. You will then loose power but damages will be avoided.

Just don't go WOT until you burn that gas. Get an octane booster in your tank just to be on the safe side.

Owners manual recommand filling with premium when you reach half tank.

 

My Acura Integra manual says "use premium octane only etc" the number of premium octane gas fillups it has seen in the last 9 years can be counted on one hand. The car has 300,000 KM (regular non synthetic oil) and no major problems, the engine as strong as it was from day one. I don't think one fillup of regular octane gas is going to result in damage unless youre FI and mapped to a certain octane.

 

I asked my dealer's mechanic lead about running regular gas in my new 35th Z. He said no problem at all and that the computer would automatically adjust for the best burn of the poor gas. The performance suffers a bit.

When gas his $3.07 a gallon I was really tempted to put mid-range or regular in but held off and put the good stuff in.

 

Just buy some octane booster fuel additive...That should treat the fuel and get you up to snuff.

 

I bet u won't even notice, that happened to my bmw like 3 times when i owned it and i couldn't notice a difference at all. DOn't go buying octane booster, just run it to a half tank and take it easy on the car and then fill up the other half with premium, u'll be fine.

 

In the words of my hero, Napolean Dynamite , all I have to say to the kid at the station is "IDIOT" Anyway thanks for the response guys, I feel a little better now.

 

Won't the computer run on limp mode?

Here in Florida we fill up with 93 octane. We have a few 91 octane stations, but that one time i filled with 91 octane my car was running on limp mode. Your ecu knows and protects the motor! Or at least just in my case??

 

Use regular fuel all the time and save some money, unless you race your Z. The main advantage of premium-grade gas is that it allows automakers to advertise a few more horsepower by designing and tuning engines to take advantage of premium's anti-knock properties. But auto engineers generally agree that if you use regular in a premium engine, the power loss is so slight, most drivers can't tell.

Today's engines use highly evolved versions of a device called a knock sensor to adjust settings automatically for low-octane gas. And more engine control computers have adequate memory to allow separate sets of instructions for various octanes. The engine control computers keep pushing to maximize performance on whatever grade of fuel is used.

The only modern engines that should really need premium are those with superchargers, which force-feed fuel into the cylinders. "You're driving along and just tramp the gas and the knock sensor cannot sense the knock fast enough in some cases," because the supercharger boosts pressure so fast, says Bob Furey, chemist and fuels specialist at General Motors.

Burning regular when the owner's manual specifies premium won't void the warranty, nor damage the engine, even the most finicky automakers say. "You're giving up perhaps just a little bit of performance that a customer wouldn't really even notice, it's so slight," says Furey.

All Porsche engines are designed for premium, too, but it's not available everywhere. "Our cars must be able to drive all over the world, and so we are able to run on regular," says Jakob Neusser, director of powertrain development at Porsche's research and development center in Weissach, Germany. "You don't have to feel that a mechanical problem or anything else will happen" using regular gas, even in the highest-performance, regular-production Porsches.

Premium, in fact, sometimes is worse fuel than regular. It resists knock because it's harder to ignite than lower-octane fuels. As a result, some engines won't start as quickly or run as smoothly on premium, notes Gibbs, the SAE fuel expert.

High-test does have a potential fuel economy benefit. It is slightly denser than lower-octane gas, meaning there's a little more energy in a gallon. But the small difference is hard to measure in real-world use, and that same density can contribute to undesirable buildup of waste products inside the engine.

http://www.usatoday.com/money/autos/...emiumgas_x.htm

 

yea, don't worry, it won't cause any harm.

 

It's the same way in Oregon. I just happened to find that out when I got out of the car to pump gas, there was no place to insert a CC, and some guy walked up to me. I'm pretty proud that it only took me about 200 milliseconds to figure it out, because normally I'm a lot more dense!

 

If the engine is operating at sub-optimal compression, we're obviously not going to get the maximum power levels, but what's worse is that we need to make higher revs to make up for the lost peak efficiency. That means at lower octanes we're burning more fuel to get the same acceleration. Is that costing more than 10 cents per gallon? I don't know but I think there's a good chance.

91 is the best I can get anyway

 

Nice research you've made.

But USAToday does not register against proper automotive engineering documentation.

I'm pretty sure if I blow my engine, for whatever reason, and Nissan learns I ran regular unleaded, they will certainly not honor the warranty!

As for saving money with regular fuel, it has so much to do with driving habit that I recommand everyone to try a few tanks of different grades and see how far they can drive. I found premium to be cheaper on the long run on my cars. The engines run smoother and have better throttle response and more linear torque delivery.

Also, octane rating is not the only difference between regular and premium fuel. Addidives are to be considered. Better atomisation properties, cleaner injectors will affect performance over the engine life.

 

Compression is fixed on our cars.

You will not have the same acceleration with regular gas because the ECU will "detune" the engine (ignition timming) to prevent knocking. Combustion will be incomplete, peak cylinder pressure will not be achieved at the right moment. Not optimal...

 

not to take over thread but, kolia hows your car doing? pm when you get a chance.

J

 

104 Octane Boost!!!

+1 on that it wont cause any problems...
+1 on the octane boost