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350z Fuel Conundrum


JimmyWhite1

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Hi All,

 

I've recently purchased a Z and I absolutely love it. I have read multiple posts, websites and guides regarding the fuel I have to use. I'm just after some up-to-date advice please because common sense tells me that when buying a second had Z, or any car for that matter, you won't get receipts of the fuel all of the previous owners have used. I currently have 98,000 miles on mine which I consider to be average, or on the low side (I have a 2003 model), so it's had a lot of fuel over the years. My engine sounds smooth, I've recently serviced it and can't see or hear any obvious noises, but should I just dive straight in and use Premium/Supreme Unleaded? There's part of me that feels like every previous owner wouldn't have forked out on expensive fuel, so they may have used regular Unleaded 95 instead, but then some forums say 95 is fine? Obviously for me, I would prefer to keep the car as long and healthy as possible, so I would sway to Supreme/Premium.

 

What would you guys do?

 

Thanks for all advice :)

Edited by JimmyWhite1
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I had similar thoughts about not knowing what the previous owner did. I'd go with the recommended higher octane. When I had my Corolla T-Sport I decided that at 5p a litre difference, 100ltrs would cost £5 more over a tank (obviously the tank wasn't that big) of regular, not worth not doing at that cost. Even if its 10p a litre more now, the odd tenner here and there won't go amiss, and lets face it you're never going to fill 100 litres, so that's less than a tenners difference.

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Thanks for the reply Jay84.

 

Great advice, I didn't think of it like that but when you do the maths and display it like that, it really isn't much different using the higher octane. I have read multiple reviews on mixing fuel too, I currently have about 1/4 of a tank from the dealer left, I have no idea what fuel they have used. It won't harm putting in higher octane on top of that will it, or would you wait until I'm pretty much empty and then just put fresh Supreme/Premium in?

 

Many thanks

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The 350z is designed to run on 98 octane or above, if you run it with lower than that (i.e. regular unleaded) then you'll get decreased performance, and worse case scenario you'll get engine knock.

 

Most super unleaded is only 97 octane, think it's only Shell and Tesco which offer above 98?

Personally I always use Shell because although it may be say 10p/litre more expensive that's nothing really when you weigh up the overall running costs of the car. 

 

Like you say, unless you've owned it from new then you'll be extremely lucky if you've got a complete record of every time it's been fueled. Like with anything on the car, all you can do is treat it right and then I'm sure it won't let you down :thumbs:

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You should run a 350Z on premium unleaded fuel yes tesco momentum or shell nitro + would be the best choice. Premium from BP and others do only have 97ron as far as I know. People will say shell is best but i have never had any problems running momentum and I have been using it for over 3 years now.

 

95ron will cause engine knock and reduced power i believe as has been said above...

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Thanks for the advice guys, really appreciate it!

 

My nearest would be a Tesco, which isn't too far, 15 minutes or so and on top of that you gain the clubcard points, so it's a win win :)

 

Regarding the fuel in my tank currently though, I have no idea what it is, is it silly to drain it and just top it up with fresh, or can I put 98 octane on top? As stated before, currently there are no obvious noticeable problems, but I've got 127 miles or so left in my current tank so if it causes engine knock then I want to avoid that as much as I can.

 

Thanks again.

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I wouldn't worry overly much about what's in it now, its not like the 2 fuels won't mix. You can buy octane boosters, but i'd just fill it with the higher octane and have done with. If you have a costco card, they also do the 99, and its a little cheaper than Tesco (I actually think its the same stuff/supplier etc), you just don't get points.

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Agreed, I think it'd be overkill to drain the bit that's left in the tank, it won't do any harm mixing regular/super unleaded so just fill it up to max and you should be fine. 

 

In theory you shouldn't get knock anyway, because the Zed has a knock sensor. If it starts to detect it then the ECU should retard the timing (which is what causes the power decrease) to prevent it. 

 

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2 hours ago, davey_83 said:

Thing is when buying from a garage/trader and they send a driver to go put £10 worth in for road test, do you reckon they'd have put the more expensive super unleaded in? errrr no

You're absolutely right, and what's more scary is think how many people want a test drive and eventually don't end up buying!

 

Thanks for all the replies guys, great help! :)

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Super only, its to stop knock, which the the fuel exploding when it shouldn't do when it's squashed.

 

I mainly used Shell VPower which is 99, any Super will be safer than normal unleaded.

 

If you end up in the sticks where you can't buy super, just put normal fuel in, ideally as little as possible, but don't nail the car until you've filled up with super again.

 

 

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3 hours ago, Wayne370Z said:

Tesco Momentum for me too.

Cheap, convenient and, more importantly, clubcard points for a free meal at Prezzo`s every 3rd month.... :thumbs:

+ For this - Although, my preference is Pizza Express ;)

 

I've opted for the Tesco momentum which to my surprise was relatively cheap. I did however pass a Shell garage on the way, Tesco garage is about 10 minutes further on from Shell, but you don't get clubcard points with shell. Is the V-power proven to be as good as momentum? - sorry if the answer is already listed here, I have only just got back and haven't actually looked.

 

I'm going to give the Z a good drive to drain as much 95 as possible, that way I can keep topping up with 99+ and knowing that I'm putting the best in.

 

Thanks again guys :)

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9 hours ago, Ekona said:

You cannot run a DE engined car on 95ron, as the knock sensor does not function once you hit higher revs i.e. 4k rpm and over. You can’t change what others have done, but please only use 97+ going forward. 

Didn't know this, good to know! Just out of curiosity, is the HR engine different then? 

8 hours ago, JimmyWhite1 said:

Is the V-power proven to be as good as momentum?

 

Pretty sure there's no definitive answer to this, if you search the internet you'll get loads of different answers but it's all just personal preference really. 

Like I said, I use Shell, but as long as you stick to anything 98+ I wouldn't worry about what brand :thumbs:

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8 hours ago, Jack94 said:

Didn't know this, good to know! Just out of curiosity, is the HR engine different then? 

Yup, it has a much more sensitive knock sensor that will happily cope with 95ron at any revs, assuming you're with making a bit less power.

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