Taller wider body means less need for length to get a given interior/cargo volume. Wheelbase is actually almost identical between the two, so look at the front/rear overhangs to see where the differences are. The Corolla has also a bit of a "pinch"/narrowing of the boot and nose which makes it look smaller than it really is, compared to the squared-off bumpers/tailgate on the Rav4.

 

vs

 

The extra 17ish percent in height also explains why the fuel economy isn't as good for the RAV4.

 

For MPG, it is the weight difference that matters more with RAV4 weighing 500~600 lbs more than Corolla...

 

Yet it is a fact. RAV4 may look bulkier but it's bigger in width and height, not length, since the Corolla sedan adds a trunk. But comparing the RAV4 with the Corolla hatchback (so both with same body styles) the RAV4 would then have advantage in length (±9 inches). Vehicles are more often categorized by passenger volume rather than sheer size as the latter may be exploited in different ways. For instance, both RAV4 and Corolla Cross are classified as "Small SUV". At almost the same size, the current Corolla sedan is classified "Compact car" while the previous 11th gen sedan was classified "Midsize car" since it managed to much better allocate legroom (more than Camry in the rear, actually !).

I wonder if that would be true at high speed?

True at any speed. MPG enemies are weight, wheel size and shape. A hatchback design is always aerodynamically at a disadvantage vs sedan. So not just size matters 😉 !

 

Yet it is a fact. RAV4 may look bulkier but it's bigger in width and height, not length, since the Corolla sedan adds a trunk. But comparing the RAV4 with the Corolla hatchback (so both with same body styles) the RAV4 would then have advantage in length (±9 inches).

There's a little bit more to it than that though. The 11th and 12th-Gen Corollas broke tradition and had the sedans on a longer wheelbase than the hatches - Corollas had been running a ~2600mm wheelbase since the 9th-gen so it was definitely the sedan that grew rather than the hatch shrinking (the 11th-gen actually had a greater difference between the two than the 12th-gen, which had the hatch wheelbase grow 40mm). The hatchback is also a "sportier" style than the SUV-wagon style of the Rav4, the Corolla Cross would be a better equivalent in that regard (since it has the same wheelbase as the hatch but the wagon style of the Rav4, and that almost halves the difference in length between the hatch and the Rav). And as a comparison, I've thrown in my 2006 long-boi 9th-gen wagon

12G Corolla sedan
Wheelbase 2700
Length 4630

12G Corolla hatch
Wheelbase 2640
Length 4375

1G Corolla Cross
Wheelbase 2640
Length 4460

5G Rav4
Wheelbase 2690
Length 4600

9G Corolla wagon
Wheelbase 2600
Length 4410

Note these numbers are from Aus-market models, which might be slightly different to US (we've also had every hatch model since 1986, and our 8th/9th/10th/11th generations are slightly different to the US)

 

I have both. It's true.