370z requires premium fuel?

frost

I ran across a website that where the topic of discussion was whether cars used for racing should switch. Here is a quote:
"Driving Habits: If you drive your show/race car just once or twice a year you may want to stay with gas because E85 works like a sponge grabbing all the water it can from the air. So driving some on a weekly basis would be good. If you use E85 keep it moving don't store it! If you need to park your car for long terms you should fill your tank with gas and stabill. This will provide you with some protection from rust and fuel system problems."

Not sure why grabbing all the water from the air would be a bad thing though. Maybe cause of dilution to the oil?

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370z OG

Crash

That's a good question. I don't know about that. You're right that there'd be dilution, and there would be a problem when it came time to run the car and your motor gets a gulp of water instead of fuel. But you also have to have special fuel lines for E85, but I'm wondering if they're stainless steel or if they can rust.

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2002 Corvette Z06 - Totaled
2003 Corvette Z06 50th Anniversary

frost

Rust is worrying enough, but changing the viscosity of the oil is downright scary. Last thing you want is premature wear because of a change to the oil. Obviously I wouldn't make the change until the car is out of warranty, but it's definitely worth looking into because you're right; you can get good power out of E85.

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370z OG

Crash

If you tune for both, you should be able to run both without a problem. The only physical changes you need to make are the fuel lines... They need to be stainless. Aside from that and tuning, there's not much more to converting to E85. I will DEFINITELY be using it when I go forced induction. I'll already be voiding my warranty, and 105 Octane is nice when you're only paying 2.40/gal!

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2002 Corvette Z06 - Totaled
2003 Corvette Z06 50th Anniversary

frost

Keep us updated as you progress, I'd like to see how that works out.

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370z OG

Crash

Yeah. Need to buy the car first! LOL

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2002 Corvette Z06 - Totaled
2003 Corvette Z06 50th Anniversary

4MYZ370

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In cal we can only get 92 octane(oc)

To get to 93oc we need to add 100oc unleaded - i,m a little off maybe with mix - but this is close

14 gals 92oc mix 2.5gals. 100oc and then drive 300miles to get the computer up to speed -- my 350Z knocked with 92oc when pushing it on the back back roads.

Some people where having problem with higher mixes then 93.? when driving around town.
More people where having problem with higher mixes then 94.? when driving around town.
Alot of people where having problem with higher mixes then 95 & up when driving around town.


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Crash

My T/A knocked at 5500 RPM with 91 or less. I can't imagine that you'd have problems running at low speeds on higher octane levels. Very strange to me.

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2002 Corvette Z06 - Totaled
2003 Corvette Z06 50th Anniversary

BalanBro

True, but the amount they pay for their regular gas is probably similar to what we would pay for race type fuel. We have it cheap compared to most of the world.

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2012 Mercedes C63 AMG P31 Sedan, ROW, aFe, Eurocharged Dyno Tune. 438WHP/415WTQ
2010 SOLD: 40th Anniversary 370z

NBZ34

In Germany, right now they're paying around $8.50/gal

Venezuela on the other hand.... $.12/gal

2011 Nismo#91

Just a note for the people using E10 gas and don't drive their car often you lose about 2-3 octane rating if you let it sit in your tank for a few weeks especially when its humid.

Rockcrawler

or aggresive timing

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2009 silver sport, 6MT touring and nav, 8700 miles when I got it, "almost" a daily driver now... bone stock aside from tint and Gemini CBE, PC'd Rays black stardust and running 275/295 DWS rubber

Augustus

A few points...

Technically, premium gas isn't required in a (stock) Z. Required as in the engine will explode if you don't use it. Per the manual, you can use 87 octane, but it's not recommended and you should avoid "spirited" driving if doing so. Using 87 in a high-compression engine means you'll get more knock. Knock = bad. Now in any modern car, the knock-sensors will detect knock and pull the timing before you even hear it. Retarded timing = less power and likely less MPG. Bad.

In my experience (based on owning several 'premium-recommended' cars over the years and being stuck at some podunk gas station that only had 87 a handful of times), running lower-octane gas in a premium-recommended car is a zero-sum game. It will cost you $3 less to fill up, yes, but you're going to see a decrease in MPG that's >= the cost you saved to fill up.

Bottom line, just put premium in you Z. It's a sports car. If you can't afford premium, buy a different car.

Actually, no, they don't. European/English gas is about the same octane as we have in the US. Like miles vs. kilometers, there is a difference in how octane is presented at the pump. In Canada & Europe, they use the straight "research-octane-number" or "RON". In the US, we use the "AKI" or (R+M/2) measurement. Nitty gritty details can be found elsewhere, but basically..

91/92 octane Euro/UK = 87 octane US
95 octane Euro/UK = 91 octane US
98 octane Euro/UK = 93/94 octane US.

So don't think we have "crappy" gas here in the US because of the octane ratings. It's simply not true. That said, there are some stations in Europe (Shell V-Power?) that sell 100 octane gas, and that equates to like 95 octane in the US, which is a notch better than what we (generally) have here. And it is true that some Euro-spec vehicles may require this, which must be slightly detuned for the US market.

Similarly, it's like how vehicles in the UK seem to get better MPG than they do in the US (for Top Gear UK fans, this is relevant). They actually do get better MPG, but it's not the technology, it's simply the size of the gallon. An imperial gallon is 4.5L whereas a US gallon is 3.8L.

gofaster87

If you want to save on fuel costs have several maps available. I have a friend that tuned his car(he is a genius at tuning) for different octanes including 87. He uses the 87 map for driving back and forth to work and running errands. He switches to the other maps depending on what kind of racing he is doing on a particular day and what octane he has available from the track. So his range is from a few hundred whp to over 500 whp.

mantella87

Excellent post. Do you have any insight as to why most gas stations in the western states typically offer 91 as the highest octane rating? I've heard so many different reasons, ranging from altitude above sea level to emissions regulations.