Downshift or dont downshift

Just wondering, if im in 4th gear and a car is turning in front of me,and i have to slow up a little to where i know i could shift to 3rd but keep it in 4th ,can that cause any damage to the motor , a friend of mine was with me the other day and I done that and he told me that it could hurt my motor

 

Yes.

Why wouldn't you do what you 'know'?

Lugging the motor is one of the worst things you can do.

I will say that if you are slow enough to lug in 4th you likely need to go deeper than 3rd. 2nd would probably be more appropriate.

 

Hmm, maybe your friend is concerned that after the car in front of you has cleared your path that you are going to hammer on the gas and lug the engine in too high of a gear.

If you are going to slowly accelerate at part throttle afterwards I see no problems, if you want to accelerate quickly you'd downshift.

-chris

 

Thanks for the info, i didnt know this ,i definitely wont be doing that anymore

 

Every time is different you just go with what you need to do .

After this long I have no idea what gear I am in.

When I get tired I try and shift to the high side

 

I usually watch the tach and if its enough to drop me below 2000rpm I down shift.

 

No, you can not damage the engine that way so long as the engine is above 1200-1500 RPMs. if you're in 4th trying to accelerate at less than 1200 RPMs all you're doing is wasting gas. Shift to a lower gear to accelerate faster. If you're under 1000 RPMs and not in first and trying to accelerate THEN you may cause some damage. Only be in a gear above first when you're able to keep the RPMs above 1200-1500.

For clarity, your owner's manual actually has instructions as to what gear you should be in for certain speeds. I think it's first gear up to 10-15mph, 2nd gear up to 20-25 mph, 3rd up to 30-35, 4th gear up to 40-45, and 5th gear for anything above. If you're cruising above 30 and ONLY cruising, no acceleration at all, you can use 5th.

 

It won't damage the motor at all. It just wastes gas.

 

One thing about low rpms is that you want to be in a gear where you can accelerate if you need to. If you're near lugging it you can't do that well at all.
My truck is an automatic...1st auto I've owned. But my daily driver is a motorcycle. I never lug it just for the fact that if someone decides they want to kill me at the very least I have the one thing the bike is good at...acceleration. Can't do that in a high gear. I just keep her around 5,000 rpms and i'm good to go.

 

What has changed over the years in the bottom end of these motors that allow for lugging ?
I can still feel the lugging with my truck if I am light on the throttle ,therefore , I dont let it lug .
On older vehicles , if you lug the engine , you rip the bearings off the crankshaft because of the thrust load . Did Toyota compensate for thrust load in some way or form ?

 

If your lugging and at full throttle for long periods of times it could cause damage. The op didn't make it sounds like he is lugging at full throttle and 1k rpms.

But a little lug in 4th to get up to speed is really not that bad. I've done it in 400whp vehicle with 300k on the bottom end. It hasn't failed yet.

 

It's pretty intuitive. If your engine is shaking and stumbling and having a hard time accelerating you should downshift. Just because you're in a high gear at low speed doesn't mean you're lugging the engine.

 

This.

I can cruise at 35mph in 4th without lugging the engine to save gas but as soon as you can tell it's bogging you need to shift. Depending on your driving style you may want to shift before to keep the revs up