Manual or Auto

Hi everyone. My name is martin. Looking at buying a 2007 Navara ST-X diesel so that I can tow a 5th wheeler. From all my homework the choice of vehicle ios between a Navara & a Colorado. My preference is the Navara. Yet Im in a dilemna whether one shoukld get an auto or Manual.
The fifth wheeler when loaded will just be under the maximum load limits.
The positives for buying a manual are the following;
control
good gear ratios for power
Cheaper to buy & cheaper for fuel
The negatives
First gear too high making a hill start difficult??
Clutches burning out under load??

The positives for an auto.
Smoother & ease in driving.
Ease for reversing.
Good first gear ratio for starts especially on a hill.
Negatives
Poorer economy
Autos get hotter quicker and may cook/

I have read a lot of reports on the web and these seem to be what owners are saying.

Has anyone experience any of these negative?
What expertise can you throw in to help me with my dilemna.
many thanks
Martin

G'day Martin, while I don't have an informed (or first hand) opinion I can only offer the advice that both dealers gave me when I was looking before I bought. Manual all the way for long and heavy towing was the similar response form both the Holden and Nissan dealers.

I test drove the Colarodo and diddn't get excited at all, still not sure if it was the car itself or the cripling sciatica pain

Cheers Brad

I prefer manual's in everyday driving but towing a auto is hard to beat.

I haven't looked into it on the D40's but I know with the R50 Pathfinder's you can get manual hub's off the D22 and bolt them on. Which make's 2wd low range an option, great for hill starts.

The D40's run Dana diff's, different to the rest of the Nissan range. But I think if you looked hard enough there may be an american 4x4 that could supply the donor parts needed to give you the parts needed for 2wd low.

But if you go a auto, upgrade the transmission cooler to a bigger unit.

Heat kills auto's, keep the temp's under control and your gearbox will keep you happy.

Dave.

I love having a manual but but for towing near the maximum load limits with the 2.5ltr engine I think I would go the auto. First gear is a bit too long, like every Navara new or old which makes hills starts a pain.

I also agree with Dave, get the largest trans cooler you can find/fit to the car and the transmission will last a long time, every auto I've ever had it's the first thing I do.

Welcome to the forums Martin.

Many thanks for your thoughts regarding my dilemna. Can I tell you it has cause me some sleepless nights. I felt like a yoyo going one way then the next. I really like your suggestion, Dave about the manual hubs. Brilliant thought. I spoke to a manufacturer that tows 3tonne 5th wheelers with both Navaras & Colorados and his option is in line with both Shonky & Dave. He would normally tow with a manual but due the the problems with 1st gearon the Navaras, he recommends auto anyday. If I wanted to tow with a manual, he told me to buy a colorado. So I have made a decision to search for a 2007 D40 STX auto. Sorry about that Nevyn.
Again thank you for your thoughts.
The next issue to explore at a later date is the suspension upgrade. Seems that some members has gone to ironman. Well another topic another day.
Thanks again. martin

The biggest problem with autos is allowing the torque converter to do a lot of the work on sustained hill climbing. If on a long climb you allow the engine revs to settle below 2,000 RPM the torque converter will be providing much of the low gear ratio.

To explain the above, at lower reves, the input to the torque converter will be turning at at much higher reves than the output. when this happens the torque at the output will be higher than the input (the effect is the same as having an extra gear box and shifting it into low gear.) When the torque converter is asked to work it produces more heat.

If you select a lower ratio in the box you will increase the speed of the torque converter and at higher speeds it does less work and thus produces less heat. Now if on a sustained climb your engine revs are around 2,000 RPM then pull your gear selector back so that you select a lower ratio and the engine revs increase to 3,000 or more

I first noted this with my previous tug (LR Discovery.) I was climbing the Gibraltar Range. This a long sustained climb that does not seem very steep, you are limited in speed mainly by the curves. The ascent climbs over 600 metres vertically. I seemed to be climbing steadily without much effort with an engine speed of around 2,000 RPM. About 3/4 of the way up the gear box light came on. My immediate reaction was panic, "what the hell's going on." I eased off the throttle an pulled the box back into 1st gear and brought the engine speed up to over 3,000. Within a few hundred metres the temperature light went out. I later found out that LR recommend spinning the torque converter at over 3,000 RPM when climbing (however it is not in the owners handbook.) Since then I have used a lower gear when on a long climb and only experienced one over temperature experience when I got a bit slack and inattentive.

If you keep your engine speed up when hill climbing you will not have any gear box overheating problems.

PeterD

^ Good advice, never really thought of that.

Dave.

Good advice Peter, after seeing the effects on exhaust temps when labouring an engine vs. high revs, it is beneficial to keep the revs up for the engine as well the transmission, when doing long hill climbs I always put up with the noise of 3000 rpm plus rather than doing 2000 rpm and watching exhaust temps sky-rocket.