Does it really need premium?

[catbobjr89]

Hey I have a 1990 Nissan 300ZX non-turbo and it says it needs premium only. With gas prices the way they are i will be broke in a month. is there any way around this, if not what would happen if i put regular in my tank?

[Jesda]

You can get away with less, but you'll noticeably lose performance on a high-compression engine.

You should have bought a Sentra!

[Bubba1]

Hey I have a 1990 Nissan 300ZX non-turbo and it says it needs premium only. With gas prices the way they are i will be broke in a month. is there any way around this, if not what would happen if i put regular in my tank?

The motor will probably knock as you apply gas, which is not a good thing.I suggest biting the bullet and put in the grade that is required. Your engine will last longer, which costs a lot more to replace than whatever savings you'd get by paying a few pennies less for regular.

I would recommend altering your driving and maintenance habits to improve gas mileage before skimping on a lower grade of gas than what is required by the manufacturer.

[JESTER]

Forget it. Run regular.

[skydragoness]

The motor will probably knock as you apply gas, which is not a good thing.I suggest biting the bullet and put in the grade that is required. Your engine will last longer, which costs a lot more to replace than whatever savings you'd get by paying a few pennies less for regular.

I would recommend altering your driving and maintenance habits to improve gas mileage before skimping on a lower grade of gas than what is required by the manufacturer.

Do what Bubba says, an older engine has a lot more crap and deposits in it already, it doesn't need more of it by adding cheapo-crap 87 octane. Sell the car if you can't afford it.

[MinisterofDOOM]

Yeah. My car's three years newer with basically the same engine. She's just recently gotten to the point where not only does low grade ping, but cheap midgrade pings just as bad. Low grade has pinged for a little while, but now even maverick and smiths midgrade (88 or 89 around here) knock just as badly. I hate that noise...as soon as it starts knocking I find the nearest decent station and pour 5 bucks of premium in...I'm going for 300k original-engine miles and it's not going to happen on cheap gas.

Mine's not nearly as performance tuned as yours, so I can't imagine putting abything but Chevron 91 or higher in a Z.

I only go to Chevron or Tesoro (or their afilliates) anymore, and I'll drive a ways to do it.

There are other ways to save money than skimping on gas. You'll damage your engine if you don't run decent gas. On newer cars, KS will retard timing and you'll merely loose power. But with the good old VG30DE, you've got to put decent stuff in, or you'll regret it in the long run.

[vicQ45]

MOD knows what he's talking about. the maxima is actually built for premium gas. check fueleconomy.gov! grocery store gas is garbage and hell on injectors(especially our old pintle-tip designs). any car with a VG deserves at least 89 from a GOOD station(chevron IS the best in most areas). i recommend using whatever the manual tells you to put in. if you wanna save gas, buy a slower car. you're just hurting a gorgeous car by putting crap gas in there

[Jesda]

I run the Q on 87. Will be going back to 91/92/93 when I get back to St Louis. Runs fine around town but loses its breath in mountain passes. No oddities. No pinging. No knocking. Still smooth as a Q.

[Mr1der]

ATLEAST go midgrade and don't get on the car too hard...

it suggest that because the car has a 10.5 to 1 CR I think...maybe just 10...

[sanioll]

Do what Bubba says, an older engine has a lot more crap and deposits in it already, it doesn't need more of it by adding cheapo-crap 87 octane. Sell the car if you can't afford it.

sky,

87 octane level gas doesnt mean it is dirty. In fact, it has more energy storage than 93 octane gas. Octane level is the temprerature threshold of the gasoline when compressed. Thus you have to run higher octane gas with high compression engines. Otherwise the mixture will detonate well before the spark plug, damaging your engine.

And people with older cars getting ping, should simply run a good cleaner through their system to clean the carbon deposits. Since there is a lot of build up, you get pre-spark detonation inside the cylinder. I suggest seafoam. Did a write up on that already, search and find.

Using higher octane doesn't make your car faster or better. You have to use the one the engine is designed for. Or lowest octane level possible, without getting a detonation. In production vehicles, I would stick with at least the recommended octane level.

[szh]

Hey I have a 1990 Nissan 300ZX non-turbo and it says it needs premium only. With gas prices the way they are i will be broke in a month. is there any way around this, if not what would happen if i put regular in my tank?

Given the typical $0.10 per gallon difference between premium and mid-grade and an additional $0.10 difference regular, is the total cost delta every month really that high?

Depending on the number of miles you drive, you will probably only see a $10 or $15 difference each month. Personally, I would much rather not muck up my engine long-term for this short-term gain.

Regards,

Z

[szh]

I run the Q on 87. Will be going back to 91/92/93 when I get back to St Louis. Runs fine around town but loses its breath in mountain passes. No oddities. No pinging. No knocking. Still smooth as a Q.

You may not hear it, but pinging and knocking is happening. You engine is trying to compensate every time - particularly on those mountain passes!

Not to pick on you Jesda, but this is just one of the reasons I will never buy a used car again - once bitten, twice shy! Even people here on NICO, who ought to know better, are not treating their cars right!

I am picky and anal about maintenance on my cars, because I want them to last a long time without breaking down. The next owner of my M45 - if my son does not get it - will find that my car was maintained beyond the call of duty and will love it as a result!

Regards,

Z

[driverdriver]

Given the typical $0.10 per gallon difference between premium and mid-grade and an additional $0.10 difference regular, is the total cost delta every month really that high?

Depending on the number of miles you drive, you will probably only see a $10 or $15 difference each month. Personally, I would much rather not muck up my engine long-term for this short-term gain.

Regards,

Z

Totally agree.

[Snelly]

Hey guys, This is one of those issues where people are completely wrong on, and unfortunetly it costs people alot of extra cash over the long run. Regular gas is not low grade or dirty or bad for your car. Don't waste your money on premium unless your engine is pinging, and if your manual says you can run regular and you are pinging you need to time/clean your engine. Regular has more power than premium, well, it's complicated, but it burns faster, thats why your car will tend to ping at low rpm's. For years I tried to figure out why my truck didn't get better mileage with premium, I thought I was tuning it wrong. It wasn't untill I bought a manual for my Ninja which told me do not put premium gas in, it won't run as good!! Regular is OK, it's what it designed to use. Please don't misunderstand me and jump my a** on this, if your car is designed to run on premium, don't use regular. My Acura Vigor is designed to run on 91 minimum, and I tried regular and it just cut out the spark or whatever it does and I had alot less power(but it never pinged) so I put premium in the Hondura, regular in the ninja and the 720. Consider mixing regular and mid range if your engine knocks, or retard the spark abit. I'm only trying to help you guys, don't waste your money on premium, it only produces better on higher compression engines, simply because it won't explode(ping) or burn as fast under the same conditions. This bugs me almost as much as drilled rotors. My bike has drilled rotors but it's only to save weight!!(and because the bike is very light, heat isn't a big deal, also there is no penalty for the loss of the surface area(and strength) caused by the holes, the front will stop me all day so less mass actually helps more than it hurts). HAHA go figure. Anyways, don't you think the oil companies screw us enough already? Don't help them anymore by bending over for them. Peace.
Modified by Snelly at 8:11 AM 9/11/2005

[gabossie]

you have a ninja? sweet! Does he chop off peoples heads when he gets angry? Why did you have to buy the manual separately, shouldn't he come with it?