2024 Prius Limited AWD Range Questions

Based on my experience, that matches the "safety margin" built in to the low fuel warnings of my past 2010 and 2012 Prius, and current 2024 RAV4 Prime. And is similar to the warning lights or just 'needle on E' gauges of most of the other-brand cars I have driven over the past half century.

Here is what your Owner's Manual shows, but my experience is that my OMs have understated the margin, the actual margins have been higher, like you have found and what Tideland describes:



MPG is far more variable than many drivers realize, depending on conditions: engine warmup status, load, temperature, rain, snow, wind speed and direction, mountain slope, external cargo carriers, etc. And the car has no way to forecast what conditions it will encounter just ahead. So most car makers put in some safety margin on their low fuel warnings to save most drivers from their own miscalculations and MPG ignorance. If the 'miles remaining' gauge truly reflected average driving conditions, then numerous drivers will get caught short on the below-average days or trips, leading to many angry calls to Customer Service with complaints like "the miles-remaining gauge said I had enough miles left to get there, but then it ran out of gas and left me stranded on a dark and stormy night [ in the middle of nowhere | far up the mountain pass road | in a blizzard | in a place with no cell service to call for roadside assistance ] ."

Building in a traditional amount of safety margin goes a long way towards reducing those angry calls to Customer Service. It won't stop all drivers from running out of gas. But for those who still do run out, the gauges and warnings will have been lit long enough for them to understand that they can blame only themselves, not the car maker.

This is just one form of 'Customer Expectation Management'. There are additional forms of it built in to most cars these days.

 

Sounds about the same as mine. My average fill ups on the light are 8.5 gal. I typically fill right when the light comes on but I feel like its usually stating higher than 20mi left at that point. I pushed it and ran the estimated range down to 1 mile last week. Tbh I didn't think about checking how much I put back in at the time.. I think Tideland is correct with the reserve quantity based on other Toyotas I have owned.

 

I get about 350 miles of displayed range in the winter(which is really about 400 miles including the safety margin), and the displayed range gradually increases to almost 450 miles by mid-summer(550 miles with the safety margin).

 

I pushed my 2010-2012 Prii past 0 miles numerous times, the farthest being about 60 miles past. Based on the refill quantity, it still had nearly a gallon left.

Another 2010 owner (I'm currently not naming for reasons not relevant here) intentionally ran that Prius (and a previous one) out of gas many times, for a wide variety of engineering and fuel and other tests, reporting many technical findings back to us. In his tests for Gen3 range (and for discovering its fuel starvation behavior), he went a bit over 130 miles past the Low Fuel warning light, which lit up about 25-30 miles before Distance To Empty fell to 0 miles.

Other drivers beware: that was a different model year, he drove at moderate speeds with better MPG than many of today's freeway speeds, took along a spare can of fuel, and carefully selected the time and area and circumstances where he'd run out of gas. Don't tempt fate by running low in circumstances where running dry would be inconvenient or worse.

Later, I ran my Subaru all the way to actual fuel starvation, and found its refill quantity dead-on its claimed amount (when rounded to the nearest tenth of a gallon). Though its low fuel warning lights had a bit less safety margin, and its Distance To Empty gauge had no safety margin. Fortunately, its earlier low fuel warning stages were more glaring, multi-colored, and harder to miss that the Prius warning.

 

I'm routinely at 0 MTE (miles to empty) when I fill up. I've actually ran my car from South Lake Tahoe back to Sacramento once (90+ miles). The low fuel indicator came on just as I crested the summit. Normally I wouldn't worry about it, but I had 2 adult passengers onboard. It was mostly down hill on the way back that gave my traction battery a chance to recharge. When I eventually refueled, there was still a 0.75 gallon in the tank, when I did the math. I was joking with my passengers, that they've have to get out and push, they pointed out every gas station we passed on the way back down the mountain.
The computers can only give you estimates - you need to make your own guesstimate under real life driving conditions. I would've never attempted the above in winter or wet driving conditions.

 

I try not to take it down near 0 MTE just because I don't want to put extra wear on the fuel pump. The pump uses the gas in the tank to keep the housing cool, and running the tank near empty can cause it to overheat and prematurely fail.

That being said, Toyota makes some of the most robust OEM fuel pumps, so you're not going to kill the pump running it near empty every now and then. But getting in the habit of keeping it near empty and only filling the tank partway up is a recipe for damage. And the side effect of the Toyota pumps being so well built is that they're pretty darn expensive* to replace. So best practice is to always fill all the way up, and try not to let the tank drop much below 1/4 or 1/8 tank(roughly 3-4 gallons).


*I think I'm looking at the correct part, and it's $520 MSRP for just the pump, and $550 MSRP for the whole pump/gage assembly.

 

Hi Steph, The fuel gauges are only one set of gauges in the newer Prii (plural for Prius) that confuse many new owners. There are many gauge set in the car that work together. You're not the only person to ask about the fuel and estimated miles to empty gauges. There are many posts asking how they work and what to expect form them.

 

Whenever I refill close to 0 MTE, it usually takes about 9.2 gallons.

Your MPG is on the low side and perhaps that is because you drive a lot of fast highway miles? When I have tanks like that on long highway road trips, I find that when I fill at 0 MTE it takes even less gas, more like 9 gallons or even less. If that is your case, mostly fast highway miles, just a guess on my part, but maybe the computer does an even worse job of calculating MTE.

(Note: My Fuelly tag below is broken - I have 61 fill-ups currently in my 2024, not 1!)

 

Legendary folk tale there. I'll agree though that this was a thing, but more so on the real old stuff. Previous gens of Toyotas for example had the venturi bucket pump assemblies with brushed motors. The returned fuel sprayed into the bucket where the pump lived. The returned fuel also siphoned gas into the bucket assembly. On my truck which I ran down quite often the pump had some apparent heat discoloration on the pump body so I have no doubt in my mind it was getting warm.

The newer pumps are brushless , and the system return-less. They only run as much as is commanded by the ECM. They aren't under nearly as much load as a constant pressure pump, and the brushless motors are inherently far more efficient and durable.

Out of curiosity I did some googling to see what the Prius pump looks like. Take a look at this monstrosity.



The pickup filter being right on the bottom looks like it will be very pretty effective at getting the last of the fuel from the sump in the tank. Compared to other fuel pump assemblies the float also seems to go right down to the bottom of the pump as well.




I've got to give it to you all, I thought I was being brave running it down to 1mi to empty. TBH I haven't really had to push it that far before but I knew there would be a lil extra in there. It's good to hear people are having success with pushing the limits.

 

Note also the more than 7300 foot descent from Echo Summit to Sacramento. That was worth probably 35-40 extra miles, compared to a level route.

I wouldn't have tried it with passengers either.

 

that's what I was counting on. I was half way through my HV battery when I hit the summit. On the way back, I was able to get the Prime pack back to 80% SOC with the addition 300-400 pounds - but it discharged quickly on those up hill legs. Just a matter of timing and avoiding slow moving traffic, so I don't break the cars momentum and chew too deeply into the traction battery. I've made this run on many occasions.
Besides, I had two pairs of hands that can push; if I ran out of gas.

 

When I fill my Corolla in summer, the range will typically show at 525 to 535 miles. As miles accumulate on the odometer, the range will typically decrease about 30% faster than the odometer increases. By the time I am to around 400 miles, it's close enough to indicated empty to refill, and I've onl;y gone that far a few times.

462,3 miles refilled with 10.35 gallons
459.8 miles refilled with 10 gallons
470 miles refilled with 10.5 gallons

With a 13.2 gallon tank, this indicates an enormous fuel reserve below "zero range".

 

Gen 2 (2008) does not have an MTE gauge, so what do you mean by this? If you were using the flashing last pip as the "0" indication, you still would have had 50 to 75 miles (depending on driving style and conditions) to actually empty.

If that is the case you consistently had 0.4 gal to 0 gal left in the tank when you filled. Pretty good considering the fuel bladder and all its issues.

Maybe, given your Gen 2 experience, you need to reshape your concept of what MTE means in a Gen 5.

 

Driving at or above 80mph sure kills your gas milage. Lol

I normally take my time while traveling, but it was better to make my trip to Chicago as quick as possible. I've averaged about 41mpg on the trip back facing a headwind. I think the trip there was a little better since I had a headwind, but I had the screen on navigation, so I wasn't watching mpg.

(I've been getting 50-60mpg this summer on regular drives.)

SM-S901U ?