Do I need to use Premium Unleaded in my '91 Q45???

[nbguy72]

I spent a rediculous $44 filling my tank over the weekend in Costa Mesa, CA and would like to know any thoughts on using lower grade gasoline. Would I be crazy to use 87 or 89 octane gasoline???

[maxnix]

YES!! Do a search for the threads.

[LAQ]

u wanna play, u gotta pay.blame the terrorists.

[Eswift]

blame the terrorists.

or just blame your state and national government for the taxes that still constitute a majority of your gasoline expenditures.

at least you dont live in the midwest where all the gasoline comes from canada and contains a disproportionate amount of sulfur, even after going through the joliet refinery. (the only refinery in the US that can even process the low quality canadian crude)

opening up alaska for drilling is sure doing us a great favor, its the same inferior crude as we already get from canada for less than it costs to make our own. sounds like we just need to throw on some taxes, and make a little subsidy for inferior gasoline. sweet.

they might want all of us to die, but those terrorists hook us up with better crude oil.

better yet, blame yourself for being a slave to big-oil.

the oil barrons in your own country are raping you and your family harder than any terrorlst could ever dream of.

[Q451990]

To answer the "why" part of nbguy72's question, here's the short of it. The Q engine is set up to run on high octane fuel. High octane fuel burns slower, so the explosion in the cylinder has a longer smoother duration, preventing knock. Knock (or detonation) is when the explosion happens too soon and "knocks" the piston head back down. Think of pushing a door open quickly but firmly vs. kicking it.

Anyway, knock can damage an engine, so Infinti designed some safeguards into the system. Your engine has knock sensors that monitor the sounds coming from the heads. If the ECU "hears" knock through the knock sensors, it will retard the timing advance to compensate. Unfortunately it's range isn't great enough to take care of all of the knock if you're using inferior fuel. If it detects too much knock the engine will also assume that you've put crappy fuel in and retard the timing permanantly (until it detects that you've put good fuel back in). So the end result of using 87 or 89 octane is poor performance and engine damage.

Look at the bright side... the differential between 87 octane and 93 octane is still about 20 cents... so as a percentage of your fuel bill, it's less now than before! Worst case scenario, it costs about $4 more (if you're running on fumes) - and I can't think of one single internal engine part that costs less than that!

Heath

[greg_atlanta]

You can always drive less.

I used to routinely make 40-50 mile (round trip) shopping excursions just for the h*ll of it... now I'm starting to realize that's $4-5 of gas round trip (wasn't much less before, of course).

There are a lot of people who will spends hours in their car to spend $1 less on a product at the discount warehouse across town. Hmmmm......

[elwesso]

Do what the MFG says. If they say to put in premium, put in premium. They obviously designed the engine and computer to run on premium for a reason.

[Eswift]

it will definitley run on a lower gasoline grade, but it will run poorly. It will adopt new fuel and timing changes to accomodate for the inferior gasoline, and you will see a very noticeable performance loss along the way.

[sultan]

read your owners manual or service manual. it states to use 91 or higher, but it says 87 may be used temporarily, but only you can only partially fill tank, and fill up with premium as soon as possible and you have to avoid full throttle and abrupt acceleration. i always use 93, 92 if station only has that, and like heath said, the difference between 87 and 93 is around 20 cents, not a large sum of money.

[nuQ]

used to go to a gas station near me(pa) that posted the amount of tax on each gallon of gas. when the price for regular was around 1.05 to 1.10, if i remember correctly, it was around 45-50 cents for each gallon that went to our government. I also remember hearing during the gulf war how all the us oil corps. put aside $ for fines that would be imposed for artificially raising the price of gas during the war. in other words, the war really did nothing to the flow or availability of oil to the us, but the oil corps. could raise the price, make huge profits, then pay the much smaller fines for raising the price higher than the market warrented. you don't think they would be doing that again,,,,do you????many different definitions of terrorists!

[Eswift]

many different definitions of terrorists!

my sentiments exactly.

[I am Technoman]

And this is were Honda comes in. I am loking for an all stock base model CRX HF . If I tune it up nice "no perfomance mods" I should get 38 to 40 miles to the gallon. Im doing this because fuel prices are only getting higher and I refuse to run anything less then 93 octaine in my 240. I will be using this Honda to be an everyday driver and soon so very soon I will have a SR20DET in my 98.

The way I see it if I can use less fuel as possable I will support oil terrorlst much less. F the terrorlst!

[Qdog]

it will definitley run on a lower gasoline grade, but it will run poorly. It will adopt new fuel and timing changes to accomodate for the inferior gasoline, and you will see a very noticeable performance loss along the way.

And your MPG will drop substantially due to the timing retard, making the whole exercise pointless (retarded ?)

[Jberger]

Here's a handy little calculator for comparing cost of gas based on Price, MPG, etc.

Had to convince my sister that trading for a new car just based on "savings" in fuel costs was a bad move.

It's amazing that people will trade a car, and lose thousands of dollars, just to save $350 a year in gas.

Well, I can't seem to post an excel spreadsheet. Ideas?

[AZhitman]

trading for a new car just based on "savings" in fuel costs was a bad move. It's amazing that people will trade a car, and lose thousands of dollars, just to save $350 a year in gas.

EXACTLY the point I've been making here against some members who advise ditching my 12 mpg Suburban (paid for) and my 14 mpg Q (also paid for) for newer, more "fuel-efficient" vehicles.

Problem is, if you replace eacxh with a similarly-equipped and comparable new vehicle, it only saves a few MPG. So what's the point?

[Q45tech]

The weight of the vehicle x the engine displacement. As the manufacturers have squeezed about all they can in mileage efficiency from an internal combustion engine meeting emissions regulations.If we didn't have to meet Nox standards all cars could operate at 5-10% better highway mileage but the cats require a 14.7 AF ratio in closed loop. The engine can function at 16.2 AF ....lean burn technology but the cats won't work!

http://www.mae.ncsu.edu/homepa...1.pdfh ... gl...i.pdf

Since OBD2 [1996] efficiency hasn't gotten much better in fact the current HP Wars have made it worse as the gear ratios have been optimized for max acceleration and the slow creep up of displacement.

Take the Maxima 3.0>3.3>3.5 liters or the 2.0>2.5 I4.......even Lexus 4.0>4.3>4.7.

[landtodd]

It's amazing that people will trade a car, and lose thousands of dollars, just to save $350 a year in gas.

My favorite car fantasy is to have $10K in Summer, 1973 when the first Arab oil embargo materialized. People were dumping all sorts of wonderful muscle cars for fire-sale prices. Gas stabilized at $0.60/gal . . .

As I've pointed out a couple of times, I would have to drive 30K to 40K a year before fuel became the 51% expense of owning my '92 Q. Okay, probably 30K with $2 gas, but you see my point (I hope).

[VimyJ]

My favorite car fantasy is to have $10K in Summer, 1973 when the first Arab oil embargo materialized. People were dumping all sorts of wonderful muscle cars for fire-sale prices. Gas stabilized at $0.60/gal . . .

As I've pointed out a couple of times, I would have to drive 30K to 40K a year before fuel became the 51% expense of owning my '92 Q. Okay, probably 30K with $2 gas, but you see my point (I hope).

Ya, but you'd be stuck with crappy handling, nasty el chepo interior, rattles, sqeaks, and an engine that would probably fail under sustained high speeds. There is a reason old Detroit iron bit the dust and it's not just improved emmission standards. Engineering and quality is why we own our Infinitis.

However, you could probably buy a Suburban for a good price right now.

[AZhitman]

Damn, Mike - You had a fan up until that last comment.

Actually, despite the faults you listed (all true), I still love old musclecars. My 68 GranSport was SUCH a blast to drive.

Next project: A 68-72 Vette.

[911/Q45]

I always fantasized about a 67 Vette, as I was 14 when they were new. When I was 30 I got a 67 convertible with a big block, tripower, 4 spd and A/C. I invested $30K and made it perfect. When I was finished I realized that I had a car that only a 14 year old would like. Muscle cars were fun to drive when we were kids, but I think we enjoy the memories of being young more than the actual experience of driving something rough, loud, smelly and clumsy that breaks all the time.

[maxnix]

Yeah, I have the same fantasies, then I ride in one and remember what a POS they were. Great alone on a runway, but lousy when they had to turn, brake, or go 30,000 miles for that matter. It's like that date you never got lucky with in high school.

No matter how much lipstick you put on her, she will never be 16 again. And your tastes have changed anyway, if you have learned anything in the intervening years.

I am certain it is the same for the ladies also. Well, maybe not when it comes to the cars.

[landtodd]

Would you REALLY pass up the chance to own an AAR 'Cuda as a *second* car? Didn't think so.

Such an investment would have made you a pretty penny by '85.

A Suburban? A Suburban?? Really now, no need to get nasty about it. (SUVs are a plague on this country foisted by government fuel-economy regs. Have you stood next to an Excursion or an H2 recently? Obscene!) Geez, all I wanted was to pick up a '59 Eldo Barritz convertible for cheap!

Of course, my last daily driver before the Q (all praise Nissan) was a '72 Eldo convertible. Guilty.

[911/Q45]

Oh no Todd! Did you have the chains and white shoes with no socks too?

[maxnix]

And the white belt and bell bottoms, don't you know?

[landtodd]

Grumble . . . ;-)