No 4th gear in A/T?

[talnlnky]

Originally Posted by bronsin

Yeah its just a stupid design to waste gas. The manual transmission can shift into fifth before being warmed up so why not the autos?

waste gas? thats one dimensional thinking sir. As said above, the car runs most efficient when its hovering in the 180's - 190's. Until you reach that spot you are wasting gas. By getting up to that point as quick as possible you minimize how much gas is wasted.

I bet under the right conditions I could do my 20minute commute to work without the temp reaching 188F (where it normally hovers). All I would need is cool temps (say 40F or lower), a light foot on the gas, and drive my normal route which is basically 35-45mph the whole way, but do it in 5th gear and use DFCO as much as possible.

Even this morning with temps around 60F when I left, it took probably half the distance for my car to get up to temp, cruising in 5th gear. A little 3rd gear action is not wasting fuel for the autos... similar to me using 4th gear probably warmed up my car in half the time.

Funny, I watched the temp this morning for the first time after changing my route to work about 2 months ago. I think I will try running 4th gear for the first 2 miles to see if it does have a significant impract, negligible, or non-noticeable.

[bronsin]

[QUOTE=talnlnky;383541]waste gas? thats one dimensional thinking sir. As said above, the car runs most efficient when its hovering in the 180's - 190's. Until you reach that spot you are wasting gas. By getting up to that point as quick as possible you minimize how much gas is wasted.

How do you know that? Have you ever tested a cars mpg driving in third vs driving in fifth to warm the engine up? When I had my ECHO all most all the driving was 5 miles to work and five miles back home. (well 65% of it) Not having an auto I was free to choose what gear I drove in. Theres NO WAY I would drive in third or fourth when I could put it in fifth.

[talnlnky]

[QUOTE=bronsin;383577]

Originally Posted by talnlnky

waste gas? thats one dimensional thinking sir. As said above, the car runs most efficient when its hovering in the 180's - 190's. Until you reach that spot you are wasting gas. By getting up to that point as quick as possible you minimize how much gas is wasted.

How do you know that? Have you ever tested a cars mpg driving in third vs driving in fifth to warm the engine up? When I had my ECHO all most all the driving was 5 miles to work and five miles back home. (well 65% of it) Not having an auto I was free to choose what gear I drove in. Theres NO WAY I would drive in third or fourth when I could put it in fifth.

dude, I just said i'd experiment with it..... also.. you can't compare 3rd gear in an auto to 3rd gear in a 5sp manual. the gearing is different. Also, yes, there will be differences for everybody. If you only drive 2 miles it'd be best (for mpg's) to drive in the highest gear, but if you drive an extended distance, you'd be better off (for mpg's) warming up quickly first then shifting to the highest gear.

you never stated that you had a short drive, so why would anybody assume such. People sometimes commute for 45mins or longer each way between work/school & home.

You have to take more than one perspective/variable into account.

[Kiz]

It's to protect the auto transmission. You don't want it going into 4th while the trans fluid is cold, it will greatly increase the wear. If you're driving round town in 4th gear then most of the time the torque convertor won't be in lockup and will slip accordingly. This slipping on cold fluid is what they're trying to minimise. Once the fluid has warmed up sufficiently it will allow you to use all gears.