Most of the automatic transmission cars I have owned in recent years really accelerated going down steep hills with your foot off the gas. Our automatic RX-8 picks up very little speed down steep hills. Doesn't the automatic RX freewheel on hills?

 

It SHOULD freewheel. I can pick up speed at nearly twice what I can on flats when going downhill, and once I'm up to speed, I just let it coast on its own. If anything I have to keep stopping it from going to fast and utterly blowing away the speed limit. Of course what gear you're in determines how freely you'll coast down...4th being the fastest with the least amount of engine braking.

 

It takes a pretty steep hill for me to pick up any speed. A little engine braking was designed into the car, and personally I prefer it to just zooming off down every hill. You can always throw it in neutral going down hills. I hate other people and their free-wheelin' vehicles, specifically on the highway in the mountains. 50mph up the hill, 90 mph down the hill.

 

I think coasting downhill in neutral in an auto might be bad for the transmission as the idling engine may not provide enough oil flow to properly lube/cool the rest of the transmission. It's also generally considered to be unsafe to roll around in neutral be it in an auto or a manual.

 

I used to think this was true but what about all the RV's you see FLAT Towing cars with auto's on the hwy over 60MPH?

 

You're supposed to disconnect the driveshaft when you tow like that, at least that's my understanding.

Doing a little searching it would seem there's a bit more to towing cars behind your RV than just hooking them up and heading off. This site (amongst others) talks about driveshaft couplers, lube pumps, axle locks and other such things...
http://www.remcotowing.com/

 

I am definitely talking about an automatic transmission. We live close to a very steep hill and my Ford pickup gains more speed in 3rd gear (manual trans) than the RX does in 4th. Even the Lincoln Mark VIII gains more speed in 2nd than the RX in 4th. We just bought the RX last week with 5000 miles on it. It has had the N flash done to the computer by the paperwork I have but it doesn't appear to get very good gas mileage. Haven't calculated it yet (not enough miles) but it went through the first half of the tank pretty quickly.

 

Expect to get about the same MPG out of the 8 that you get on the Mark VIII. It's something we all have to live with. I can get 20 MPG but that is on the higher end for most drivers. The other vehicle you mentioned have more weight in front than the RX-8, that “pulling” effect can be a factor. I also do not know the transmission gear ratios of others, yours are.


1. 2.79
2. 1.55
3. 1.00
4. 0.69


Plus the rear axle ratio is 4.44 all factors in this “ down hill” issue.