500X Fuel Economy question

[ronbo10]

We've put about 1800 miles on our 2017 500X AWD so far. I've been running 87 octane and have been getting around 23-24 mpg, all suburban driving. We bought it in March, so initially I think winter gas could explain the relatively low figure. The center multi-function display (MFD) seems to be slightly optimistic in fuel economy readings (e.g. 23 mpg on MFD is likely to be about 22.6 mpg or so hand calculated).

The other day I stuck in 89 octane from a Lukoil station (never have used Lukoil gas before, but I didn't want to push it, as we were nearing empty, and this station was convenient). So now this tank is reading about 31 mpg on the MFD so far, only about 50 miles into it though. I really wasn't expecting that, and am pleasantly surprised. Usually I try to use BP (or Shell) because they're Top Tier, and I've had good FE results using their gas in our 500L. 31 mpg might make me a convert over to Lukoil, if this turns out to be repeatable.

Have any of you 500X owners tried anything other than 87 octane and achieved better FE results than what you get with 87?

[datasage]

My normal driving is like 20% city roads and stop and go traffic. And 80% freeway's where i can go 70 mph. My average according to the car computer is about 26 mpg. If I go on a road trip with more freeway driving I can easily push closer to 30. Likewise if i have a week where I do alot more city driving than usual, it will drop to 23-34 mpg.

The range for the 500x is pretty significant. It does poorly for low speeds and lots of stop and go. But does ok for freeway driving.

[PLP]

The other day I stuck in 89 octane from a Lukoil station (never have used Lukoil gas before, but I didn't want to push it, as we were nearing empty, and this station was convenient). So now this tank is reading about 31 mpg on the MFD so far, only about 50 miles into it though. I really wasn't expecting that, and am pleasantly surprised. Usually I try to use BP (or Shell) because they're Top Tier, and I've had good FE results using their gas in our 500L. 31 mpg might make me a convert over to Lukoil, if this turns out to be repeatable.

Have any of you 500X owners tried anything other than 87 octane and achieved better FE results than what you get with 87?

After the whole tank, or better yet - after at least 3 of them report back with results. I can get MFD to tell me 38 mpg after coming back from gas station only to drop to regular 23 on the very next day. It all depends on the style and road you are going on.

[ronbo10]

After the whole tank, or better yet - after at least 3 of them report back with results. I can get MFD to tell me 38 mpg after coming back from gas station only to drop to regular 23 on the very next day. It all depends on the style and road you are going on.

No question about that- I will say that the driving environment that produced the 31 mpg wasn't so different from what I typically encounter, but time will tell. I'll use the same gas for the next 3 tanks and see if there is any real uptick in FE, and will post my results.

[Fiat500USA]

If you can keep the car running in the higher gear ranges you can see a huge difference in gas mileage. City and stop and go is going to be tougher. Anyone who wants to hyper-mile the car can try shifting the car manually and can probably best the computer. Shifting under 2000 rpm will generally yield best results depending on conditions. When I drive and look at the tach, the TCM generally has selected a gear that produces +-1500 rpm for cruising. I drove the car yesterday and around 35 mph the TCM selected 5th gear. At 38 mph, if I drove carefully, I could get the car to shift itself into 6th.

[davevoss]

We've put about 1800 miles on our 2017 500X AWD so far.

Your engine is not even close to being fully run-in, and so you can expect the fuel economy to increase over time, say over the course of the first few oil changes. I have ~44k miles on my 500X, and the fuel economy continued to slowly increase until mileage was close to 30k.

Have any of you 500X owners tried anything other than 87 octane and achieved better FE results than what you get with 87?

I've used 89 octane since new, some may argue that 87 is okay (like the literature says), but I regularly achieve 30+ mpg on the freeway (at speeds between 60~70 mph), and never less than about 24 mpg on back roads and around town. Last weekend I traveled 300 miles on the freeway, loaded inside and with a full size mattress on the roof, and managed to achieved 28 mpg. I always fuel-up at a big-brand station (Shell, Chevron, Valero, etc.) and avoid the no-name independents, which I think can make a difference too, at least in consistency.

[ronbo10]

Thought I'd update on observed fuel economy on our 500X. I recently filled up with Lukoil 89 octane, zero'd out the MFD, and for the first time I drove it on a 220 mile round trip that was a mix of suburban, highway and urban. I was quite pleasantly surprised- despite hitting some pretty bad stop and go rush hour traffic (the 2 hour drive out turned into a 3 hour return due to the rush), I managed 35.3 mpg. Even allowing for about 1/2 mpg error, (and sometimes the MFD is right on), nearly 35 mpg for the conditions was, I'd have to say- excellent, esp. given the poor mpg the press always seems keen to report. And this with winter gas (or, at least I'm pretty sure it's winter gas by now). On the outbound leg I was managing just shy of 38 mpg, though there is a net 200 feet drop in elevation which could account for some of that. Still, even on that leg the traffic and luck with traffic lights were far from ideal for great FE.

So yes, very pleased with that. Current mileage totals about 3,800 on our AWD Trekking, with tires inflated to 36 psi all around. Our X remains trouble free and a delight to drive. I think I've come to a better understanding of how the transmission programming functions (in "Auto" mode only though- haven't really had much use for the other 2 modes so far), and I think having some patience with and acceptance of its propensity to up-shift early and often can help with the FE you can achieve with this car. I realize that's probably true of most cars with similarly behaving transmissions, but perhaps this is especially so with the 500X's ZF 9 Speed.