1HZ vs 1HD-T - Pros and Cons (1 Viewer)

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Hi all, I am new to the site and I'm considering buying either an HZJ80 or HDJ80 LHD and importing to the US. Admittedly, I suck at using the search function, but I'm surprised that I've been unable to find a breakdown of the differences - good and bad - between the 1HZ and the 1HD-T engines.

In an effort to educate myself (and others), I'd like to solicit the opinions of all crusty, old, curmudgeons on the vices and virtues of each engine. What do people like about one and not the other? What can you do with one that you wouldn't do with the other? Would I run into trouble trying to throw a modest turbo onto a 1HZ? Does one really shine where the other doesn't, or are they fairly comparable? All thoughts, facts, opinions, and superstitions welcome.

I'm looking forward to hearing your responses.
 
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The 1HD-T is superior.

1HD-T has a factory turbo, direct injection, more power in stock form. There are issues with BEB's but that is fairly easily addressed. There is a lot more reliable power potential as a result of the direct injection system.

1HZ has no turbo and is indirect injection. Indirect injection is a major downside if you are after any kind of power. It can be turboed but somewhat marginally - there is a reason Toyota chose direct injection on the turbo variant.

I haven't driven a 1HZ powered 80 but my 1HD-T 80 isn't exactly fast so I can imagine the 1HZ variant could be frustrating on North American highways.
 
Last edited:
Joined
Jul 18, 2022
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Yeah, that is something I was wondering about. Would a 1HZ be sluggish pulling an 80 series at 70mph down the highway?

There is a lot to be said about reliable power from a factory turbo, but if the 1HZ can perform well enough without a turbo (or a meek turbo), then it would be a bit of a draw.

For me, I drive like an old lady. But even old ladies have to pass trucks on the highway.

Thanks for the insight.
 

ClemsonCruiser

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I swapped a brand new 1HZ/H55 into my 1997 LX450 with a turbo running 10-12psi, intercooler, 3” free flow exhaust, etc. it was great on backroads and especially off-road but fully loaded for a trip with the wife and kids trying to keep up on the interstate was WORK. If I’d had it to do over again I’d go 1HDT or 1HDFT so much more potential for safe reliable power with the DI diesels.

Biggest upside in my opinion to the 1HZ is it’s still in production today so parts should be available for a long time to come, the 1HDT hasn’t been in production since the early 90s so parts can’t be a little more tricky though it does share some basic components with the 1HZ.

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Joined
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Warrenton, VA
I swapped a brand new 1HZ/H55 into my 1997 LX450 with a turbo running 10-12psi, intercooler, 3” free flow exhaust, etc. it was great on backroads and especially off-road but fully loaded for a trip with the wife and kids trying to keep up on the interstate was WORK. If I’d had it to do over again I’d go 1HDT or 1HDFT so much more potential for safe reliable power with the DI diesels.

Biggest upside in my opinion to the 1HZ is it’s still in production today so parts should be available for a long time to come, the 1HDT hasn’t been in production since the early 90s so parts can’t be a little more tricky though it does share some basic components with the 1HZ.

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Wow, that is a fantastic conversion. You've got a functional hood scoop and everything - well done!
 

OGBeno

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I swapped a brand new 1HZ/H55 into my 1997 LX450 with a turbo running 10-12psi, intercooler, 3” free flow exhaust, etc. it was great on backroads and especially off-road but fully loaded for a trip with the wife and kids trying to keep up on the interstate was WORK. If I’d had it to do over again I’d go 1HDT or 1HDFT so much more potential for safe reliable power with the DI diesels.

Biggest upside in my opinion to the 1HZ is it’s still in production today so parts should be available for a long time to come, the 1HDT hasn’t been in production since the early 90s so parts can’t be a little more tricky though it does share some basic components with the 1HZ.

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1HD-T were put into HDJ100’s for the General Market till the mid-2000’s.

;)

👊
 

ClemsonCruiser

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1HD-T were put into HDJ100’s for the General Market till the mid-2000’s.

;)

👊
I knew I shouldn’t have ventured out of the 45 section 😆
 
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Kamloops, BC
For me, I drive like an old lady. But even old ladies have to pass trucks on the highway.

I pass trucks on the highway all day long in a stock 2H and my N/A 1HZ is leagues faster. I can't wait to see what its like after i turbo it.
 

SNLC

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I swapped a brand new 1HZ/H55 into my 1997 LX450 with a turbo running 10-12psi, intercooler, 3” free flow exhaust, etc. it was great on backroads and especially off-road but fully loaded for a trip with the wife and kids trying to keep up on the interstate was WORK. If I’d had it to do over again I’d go 1HDT or 1HDFT so much more potential for safe reliable power with the DI diesels.

Biggest upside in my opinion to the 1HZ is it’s still in production today so parts should be available for a long time to come, the 1HDT hasn’t been in production since the early 90s so parts can’t be a little more tricky though it does share some basic components with the 1HZ.

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Actually the 1HDT was ran in 100-series (and 80’s till 97) until the mid 2000’s in specific markets. Parts for a 1HDT are more plentiful and easier to get than 1HDFT parts.

Cheers
 
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I have a 1HZ with 464kms and has been turboed for 50km now non intercooled and it definitely does not get babied. The 1HZ is a fine engine and does take a turbo well within reason.

I had an 80 series with a 1HZ 5spd and it was slow. I put a G Turbo and FMIC on it and it was quite peppy and a blast to drive even when laden.

I think you’d be happy with either choice. If you’re chasing max power than a 1HDT would fit you better given the idi vs di.
 
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My 80 has a 1hz. It is nearly at 688 k km's. Original motor. Never driven any other 80. 1hz's have one key advantage - lugging. But yes they are lower power output than 1hdt. Also 1hz is a very simple motor and is used in lots of Toyota's of the 90's (75's, 80's, coaster buses, even 79's for some markets). Parts quite easy to get here in Oz.

I'd like to replace the 1hz with a 1hdt but need about $10k to buy an 'import' motor from a Japanese motor inporter.

1hz's are not made for turbo-ing but people do it. 1hz heads are prone to cracking if overheated.

Never rebuilt a diesel motor so from a technical perspective I dont know much more.
 
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Yeah, that is something I was wondering about. Would a 1HZ be sluggish pulling an 80 series at 70mph down the highway?
Yes being non-turbo it's great on flats but loses power on grades. However I've towed a loaded car trailer (2.5 tonnes ish) a few times with my n/a 1hz 80 and who gives a s***e how much you gear down and how slow you go up hills. It's not about speed - it's about reliability. 1hz and 1hdt are both reliable. My 80 has a h150f 5-speed manual box too so 1st and 2nd gear are slower than 1st and 2nd in a h151f box.
 
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1HZ = N/A engine and (I.D.D)
1HD-T = turbo engine (Direct Injection).
conclusion : stay away from the 1HZ (unless u have a deep pocket). get the 1HD-T (ease of mind, fill the tank and drive).


ps : i've driven all models of land cruisers.
 
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The 1HZ uses more fuel to produce more heat and less power. The higher compression and weaker pistons mean it must be run carefully with a turbo. It makes no sense to take that if you have the option of a factory turbo engine.

1HD-FT is your best bet. But probably hardest to find. 1HD-FTE is possibly the best diesel Toyota made, but they'll be harder to transplant.
 
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1HZ = N/A engine and (I.D.D)
1HD-T = turbo engine (Direct Injection).
conclusion : stay away from the 1HZ (unless u have a deep pocket). get the 1HD-T (ease of mind, fill the tank and drive).


ps : i've driven all models of land cruisers.
Nothing at all wrong with the 1hz. Mine is just about to click over to 690 k km's on the original motor. Def doesn't run like a new motor. I would *never* consider adding a turbo to a 1hz unless it was 300 k km's or less.

I would gladly replace the 1hz in my 80 with a brand new crate 1hz but I'd also consider a crate 1hdt or a jap-import 1hdt. Just don't have the $10k plus required to source a replacement motor.
 
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Here's Bosch Guru and owner of Berrima Diesel Reinhard Leimroth explaining why he loves to Turbo charge Diesels like the TD42 and 1HZ.

I almost bought a Land Cruiser with a 1HZ. Only reason I passed on it was that it was a soft top.


Rocky Mtn Hilux

🇨🇦
 
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I don't dispute any of that, *but* would someone be able to justify spending several thousand on a turbo kit for a 1hz with as many km's as mine (close to 690 k km's) and a *lot* of age wear? I do change oil regularly (every 10 k km's with a new genuine filter also) but I've only owned it since 505 k km's (since 2011).

Maybe with a very new (crate, or under 200 k km's on odo) 1hz it's worth it. My current 80's 1hz doesn't justify it.

There are places that sell on ebay/gumtree/etc. doing fully reconditioned + turbo upgraded 1hz's for around A$12k but I don't know what turbo kits are used.

How does a 1hz with turbo kit added get 'tuned'? What can actually adjusted/changed?
 
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Hello,

A 1HZ is simple, reliable and easy to repair. It is still in production, and parts are easy to get. However, it may not have enough power to venture outside the slow lane of a US highway.

A 1HZ uses indirect injection. It is possible to add a turbo and an intercooler, provided it is a low-pressure setup, i. e., up to 10 psi.

The 1HD engine has direct injection and a turbo. The 1HD-FT was used in the 80 Series until 1997. These are just becoming old enough to import to the US. 100 Series had the 1HD-FTE until 2006.

The 1HD engine is, so to speak, plug and play. No need to tinker with the turbo or other settings.

I would either get myself an 80 Series with the 1HD engine or wait until 2024 to get myself a 100 Series with the 1HD-FTE engine.

If I had an 80 Series with a 1HZ engine, I would add a low-pressure turbo and intercooler.





Juan
 

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