Honda CRV with CVT and Coasting
 

2018 Honda CRV EXL has a Continuously Variable Transmission (CVT). I use coasting (under 45 mph) around town to get 33-37 mpg. I had the CVT checked at 30,000 miles and there was no appreciable filings in the oil. We'll be taking a longer trip and I would like to know the damage that I will do if I coast downhills and put it back in gear at speed (probably 60 mph - Texas is 75 on highway). Will this damage the CVT? Should I try to match rpm?

Edit: should have mentioned that it is "engine on" coasting.

Towing info is attached.

I am no expert on CVT's, but I would think you should be alright. I'm sure the engineers at Honda thought of the possibility that someone might coast. The one thing that may be problematic is if you coast with the engine off since the transmission's oil pump is driven by the engine, so the transmission will not be lubricated or cooled if the engine isn't running. I imagine that's why the manual warns against improper towing since people typically tow with the engine off.

As for rev matching when going back into gear, I think you would be best off letting the PCM take care of that for you. If the PCM sees fit, it can increase RPM automatically via the electronic throttle to ensure smooth engagement. I imagine it goes back into gear smoothly while rolling?

I've got a CVT in my Nissan Versa. I've never tried neutral coasting in it and have no plans to try it. CVT's usually aren't as durable as standard automatics therefore I don't think it's worth taking the risk for the small amount of gas savings. I wonder how much stress returning to gear at highway speed would apply to the belt/pulleys.

My understanding was that pretty much all reasonably modern automatic transmissions (almost anything with an electronic throttle) will automatically rev match when going back into gear so the engagement isn't harsh or damaging, but there could be exceptions.

Another consideration is that unlike older Honda CVT's, OP's CRV has a torque converter. As long as the torque converter is unlocked when going back into gear (and I'm almost certain it would be), the fluid coupling will provide quite a bit of shock dampening even if the rev match isn't perfect.

@Joggernot
Have you tried coasting in N and achieved any MPG improvements?

I drive a 2017 1.5T Civic also with a CVT which maybe has the same engine as your CRV. I tried a lot of coasting in N but I have the feeling that it doesn't change the fuel consumption at all.

My understanding of a Continuously Variable transmission is being tested. :confused:

Yes I try. EPA is 28/34. I think Fuelly gives the average as 26 for regular drivers. I live on flat land by the Gulf, so the biggest hill is the bridge to Corpus Christi. I normally get 28 to 31 around town and slightly more (33) at 75 on the highway. These are calculated values; the car says a little over 2 mpg more than calculated. My high for a trip over 50 miles is 41 (20 mph tail wind); my low is 24 (headwind). Now we're into winter gas so it won't be very high for a while.

BTW I tried going 55 (minimum allowed) on the highway, and won't do it again. MPG was at 38, but the traffic was worrisome. Highway speeds in Texas are 75 to 80 mph.

And what about the two coasting methods? Did you see any differences in fuel consumption when coasting in D versus coasting in N?

Someone in the Honda Civic Forums wrote that:

There is a little engine braking with the car in D. In N the car coasts a long way before I have to put it in gear. The instant mpg readout is the same whether in D or N. Fun test...I put the Scan Gage on the car when I first got it and did some tests. With the car in D and letting off the gas, it goes into DFCO (9999) for about a half second, and then the CVT adjusts and seems to match rpms with accompanying gas use. In N the engine simply drops to idle.