This is kind of a difficult concept to describe, but I love wonderful things that are at least on some level ridiculous. I love things that show incredible levels of thought and innovation, but for very questionable goals.
I think the dual fuel gauge setup used in a few Nissans in the late 1980s is one of these things, and I think it may also be one of the best analog fuel gauges ever to be installed in a production car. I’m also absolutely astounded and baffled that it was ever approved, especially for the vehicles that ended up getting it. Off we go.
I was alerted to the existence of these fuel gauges by ex-Jalop Andrew Collins, who has one on his $100 1984 Nissan 300ZX:
Okay, see what’s going on there? You have a normal, conventional fuel gauge, then, once you get down to a quarter tank, you have a whole entire separate fuel gauge, calibrated to show you, in hash marks denoting 0.6 gallons each, just how much fuel you have until empty.
So, in simpler terms, you have one fuel gauge for the whole 19 gallon tank and a separate one for the last 4.75 gallons.
I looked it up in the owner’s manual for this era of 300ZX, and found that it seems to have been known as the Dual Type fuel gauge, with a “main gauge” and a “sub gauge”:
This is amazing. I adore it. And, as someone who was usually broke enough that I knew just how far into that quarter-inch-long red “reserve” area of my old Volkswagen’s fuel gauge I could go before I ended up stranded, I can see how valuable this would be to broke-ass drivers everywhere, squeezing as many miles as possible out of a quarter-tank of gas.
But that’s also precisely why I find this so baffling: Why was Nissan putting this amazing skinflint-enabling tool on their halo sports cars?
Nobody was buying a 300ZX for the fuel economy—a gauge like this would be the kind of thing a 1980s Sentra buyer would want, not someone in a 280Z or 300ZX, right? Wouldn’t you want this on an economy car, where the owner would be most likely to really want to keep an eye on the dregs of a tank?
But then again, putting this dual-gauge system on a cheap car doesn’t make that much sense because there’s a good bit of extra hardware involved here. Not only are there two separate dashboard gauges, but on the tank side there are actually two entirely parallel fuel sender systems with separate floats and potentiometers:
That’s basically doubling the amount of hardware needed for a fuel level sender, which, of course, is not cheap. Providing the extra, more granular-level gauge wasn’t just an easy, software-based thing to add that cost very little, like how similar functionality was provided in cars with digital dashboards (like Chrysler Town & Country minivans and ’90s Toyota Crowns) but rather required a decent amount of entirely new hardware.
I’m amazed they decided this was worth it. I mean, don’t get me wrong, to me it’s absolutely worth it, but how the vehicle planners at Nissan convinced the money people that building in a second fuel gauge was going to sell more cars remains a glorious mystery to me.
I reached out to Nissan to see if I could find out a bit of the thinking behind the dual-gauge decision, and to see just how many vehicles ended up using this, and here’s what I was told:
So, not only did the Z31 have these dual fuel gauges, but the S130 along with some of the Hardbody models from the same era had them as well.
Specific to the Z’s, the rationale behind the additional fuel gauge was mostly to add to the GT car experience. GT meaning Grand Touring of course. The 280zx and 300zx (z31) were designed with more luxury and GT spirit versus the previous S30 generation.
Although they did maintain the performance DNA of past Z’s, especially with the turbo models, the materials and technology that were found in these Z’s could allow for much easier and more comfortable long distance traveling.
The thought behind the additional sub 1/4 fuel gauge was to provide the driver more accurate information on the remaining fuel so drivers could be more attentive between fuel stations.
OK, so we have two generations of Nissan Z sports cars, and some of the Hardbody pickup trucks, neither of which seem like vehicles that had potential buyers who routinely sought to keep hyper-close tabs on every gallon of fuel in their tanks.
Here’s how the extra 1/4 tank fuel gauge looked on Nissan Hardbody dashboards:
On the trucks, the gauge is labeled “SUB” and isn’t just inset into the main gauge. It has its own place of pride and honor above the main fuel gauge.
You couldn’t buy a Rolls-Royce in this era with such an advanced dual-gauge system. Imagine being, say, a valet in 1989 and having a five-year-old Nissan Hardbody as your daily, and getting into a new Rolls-Royce Silver Spur and looking at the dash and seeing the same kind of bullshit gas gauge that a fucking Yugo has!
Think how good you would have felt getting back into your humble truck, knowing that one of the most expensive cars on the market couldn’t hold a damp candle to your beater, fuel-gauge-granularity-wise.
I mean, I can’t imagine this was coming up all the time in focus groups. Were there getting people trying out the new Z31 generation of Nissan sports cars and saying, “I love the new pop-up headlights and the way that turbo whines, along with the balance of that V6 engine and rear-wheel drive, but I sure would love to know when I have exactly 1.75 gallons left in the tank! Can you guys do that?”
I’m not sure I find Nissan’s answer that the dual gauge system’s existence was to “add to the GT car experience,” partially because they also stuck this on decidedly non-GT-car trucks, and partially because, uh, I don’t know, that just doesn’t seem like enough to justify the expense?
But maybe? I mean, it certainly adds a fantastic bit of extra geeky charm to the cars, and it’s an actually useful thing, not just some meaningless showy bit of tech wankery, like the talking cars of the era.
I think I’m just going to appreciate this as a beautiful, unknowable mystery. Another example of those times when a mass-market carmaker somehow rises above the base needs of profit and market share and perception and throws in some improbable, compelling, and charming little detail that nobody was ever really expecting or demanding.
Anyway, way to go, 1980s Nissan. Thanks for surprising me.