Vvt-i Engine

December 18, 2004

last week i discussed with my friend toyota's new technology, VVT-i engine

But u know wut? he said this to me "VVT-i engines has a short operation time"

I just wonder if anyone could gimme any resource or hyperlink to prove his words cuz i couldn't find anything bad about VVT-i, u know, i presume all of us believe toyota company wouldn't create a new tech that disappoints us

December 19, 2004

Very unlikely. Its only variable valve timing. Its been around a few years now, any design flaws would have shown up by now. The only possible reason for saying such a thing is that highly tuned engines do have a shorter life. Its why bike engines dont last as long as normal car engines. Everything is stressed higher.

The latest BMW engines that have VVT use Toyota technology apparently. Toyota developed the VVT system for them as they have for Renault and several other companies who are now using VVT also.

Currently I believe the car companies are using this technology in order that their engines can meet ever more stringent emmisions regulations but still meeting the publics want of reasonable performance.

December 19, 2004

Very unlikely. Its only variable valve timing. Its been around a few years now, any design flaws would have shown up by now. The only possible reason for saying such a thing is that highly tuned engines do have a shorter life. Its why bike engines dont last as long as normal car engines. Everything is stressed higher.
The latest BMW engines that have VVT use Toyota technology apparently. Toyota developed the VVT system for them as they have for Renault and several other companies who are now using VVT also.

What's highly tuned engine?

And i do appeal on ur quote for BMW using VVT engine which is designed by Toyota, can u gimme the information where u get this from plz?

December 20, 2004

Take a look at http://www.ukcar.com/features/tech/Engine/vv/vvt_3.htm and

http://www.corollaperformance.com/TechInfo/VVTLi.html andhttp://www.billzilla.org/vvtvtec.htm

I heard from one of the engine design engineers at Lotus when I worked there earlier this year that the BMW version of VVT was developed for them by Toyota though I have no proof of this. Lotus of course now use the Toyota 190bhp vvti engines and Toyotas 6 speed gearbox in the Elise and Exige.

All engines wear out eventually, but generally speaking the higher the level of tuning (more bhp per litre) the shorter the engines life will be before it will need re-building (overhauling). If you look at the extreme of tuning and look to things like F1 engines where they are extracting 600 + bhp from 3 litres (200bhp/litre) and dragster engines 1500 bhp from say 7 litres then you will see that those need to be re-built after only a fewhours of use. On the other extreme you find that many of the old 7 litre American gas guzzler engines produced only perhaps 200 hp(even the muscle cars were only around 400hp) which is only 30 to 60 bhp/litre.These engines will run for many years and many hundreds of thousand kilometers simply because they are so under stressed.

Toyota now have VVTL-i which is more like Honda's world famous V-Tec engines, which are also very reliable. I heard a recent report on a TV motoring progam that Honda have not had even one reported failure of their V-Tec system in all the years they have been making them ( I wonder if Toyota can make the same claim)

December 23, 2004

( I wonder if Toyota can make the same claim)
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Not really I'm afraid, the 1.8 VVT-i in the Avensis is starting to appear to be quite a weak engine, there are lots of the them burning huge amounts of oil if you read into the Avensis forum, the manual says that's it's normal to burn upto a litre every 1000 miles which is outrageous but some peoples are exceeding that and are having new engines fitted under warraty because of it.

To be honest, I find the smaller VVT-i's to be a bit harsh from personal experience and certainly not as smooth as the old engines like the 2.0 3S-FE and 1.6 4-AF which date back years.

However I do agree on Honda's V-Tec engines, had a few of them too and they are simply works of art.