What motor lasts longer

[MBTRAC]

Question regarding European cars and the statement that European driving is not relevant to USA. I lived there, owned a diesel, and drove it 90,000 kilometers or roughly 54,000 miles in 3 years. They drive a lot. For example they say Paris is home to one million cars and 700,000 parking spots so there are at least 300,000 cars on the road at all times and having driven there a lot I have no reason to doubt it. The general rule I heard from my everybody living there was 200,000 km for a gas engine car and 500,000 km for a diesel equivalent. I hated to leave my diesel there when I returned to America because of the fuel economy and drivability. A diesel has so much better low end torque that you never want to return to a gas clunker, but alas that is what we are stuck with in America. After returning to America I still had to travel to Europe a lot for my job, but then it was rental cars. I always dreaded getting stuck with a gas engine car due to the poor fuel economy and difficulty driving a gas manual in heavy traffic - the constant shifting due to the narrow torque band. But in Western Europe the diesel is relatively consistent although my car came with a recommendation to buy only specific fuel brands (and they had a list of about 6 for each country) for longest FIP life. In the USA the fuel is very inconsistent. At work I had access to repair data I could break down in any way I could dream of - dealer, state, type of job, region, etc. Selecting one machine I found a 4 to 1 difference in FIP failure rates between the best and worst regions. Analyzing the claims I found the difference to be fuel related. That is what the car Diesel engine makers told me is there reason for not supplying them in America although they may build the vehicle in America for export to Europe (Voyager minivans were very popular in Europe in the 90's, every one I saw diesel equipped).

Despite your personal experience, conclusions you may have drawn from heresay & general impressions gained during your European travels, readily available statistics do not support your perspective:

1. Comparatively the Annual Vehicle Kilometres Traveled (VKT) for Europeans remains relatively low
France - 13.346kms/8,292miles Source: Observatoire Economique et Statisque des Trasports 2007
Germany - 12,501kms/7,767miles Source: Deutscher Verkehrs-Verlag 2007
USA - 19,850kms/12,334miles Source : US DOT Federal Highway Administration 2007
Australia - 16,302kms/10,128miles Source: Australian Bureau of Statistics 2007
The same statistical sources indicate the frequency of vehicle individual trips is far greater in Europe & on a percentage basis very similar to the greater VKT variance in USA & Australia vs France & Germany

2. Average Vehicle Age (unless otherwise noted data sources are as per VKT)
France - 6.2 years @2007
Germany- 7.8 years @2007
USA - 10.4 years Source: Polk & Partners research 2012
Australia - 10.0years @2007

For France extrapolating VKT & average vehicle age, " The general rule I heard from my everybody living there was 200,000 km for a gas engine car and 500,000 km for a diesel equivalent.0,000 km for a gas engine car and 500,000 km for a diesel equivalent" would take signifanctly longer to attain than in either the USA or Australia.

Unfortunately,European maintenance/lifespan statistics are not relative to US, Canadian, Australian ..etc markets for many varied reason's, including:-
- Most European passenger vehicles/SUV engines are under 2.5litres (c.153CI) for historical reasons of capacity linked road taxes & rarely exceed much beyond 3litres *c.183CI)
- Geography/Population density means than annual European mileage is much less, with a predominance of short hauls often where the engine does not reach/sustain operating temperatures with consequential effects on wear/durability
- Still the preference for manual gearboxes in Europe, in unskilled hands an auto is more sympathetic to the narrow lower RPM/high torque ideal operating characteristics of a diesel engine
-..etc...
As well as the considerable fuel related differences you have alluded to.........

 

[Soundguy]

yep.. the diesels do seem to sip fuel pretty good.

True, the old fords diesels seem to be weaker than most. But, the gas engine is still sucking a lot more fuel and the amount of work you can do between the two is about as identical as you can get.

(and yes, its about impossible to draw a straight line conclusion ! Too many cases where either side is equally correct (or equally wrong) depending on what reference you look at. )

 

[daugen]

My question was about Perkins gas compared to Perkins diesel.

sorry, my error, I have zero experience with Perkins gas, but my understanding is that Perkins is/was the Brit's best high volume builder, and the installed car/truck/marine/industrial base is pretty big.
I bet if you bought a larger Generac generator in England, they'd offer Perkins instead of their Vanguard clone. Or a Ford four cylinder, which is I'm assuming built somewhere in England.

I think generators offer an interesting look at the gas engine market, for once past the ability of a two cylinder engine to power them, now one is looking at small gasoline car engines,
which gets closer to tractor engine size. Likely Ford has a big part of that market, as does GM. Run a car engine at 1800 rpm constant speed and it should go a long long time if the oil is changed and if the cooling system
doesn't fail and it gets clean fresh fuel. And if it doesn't have the equivalent of a 100,000 mile cam chain replacement designed in. Lot of ifs... Tractors are likely to need to run at higher rpm than that to get adequate pto horsepower unless it's an "eco" set up. But when not running a mower, or something that really requires
higher rpms for design or power reasons, the slower that engine runs the better in my book as long as operating temp is in range. Once you slow the motor down, I bet gas starts closing the longevity gap with diesel.
And I think that gap closes even faster if one is using propane/LNG.

 

[murphy1244]

Once you slow the motor down, I bet gas starts closing the longevity gap with diesel? But if you did the same speed to the diesel, it would run almost forever.

 

[daugen]

good thing I didn't say "quickly closing". I agree.

 

[Carl Bert]

Me thinks the underlying perseptions of almost everyone, makes the diesel seem like the answer. Those perseptions are very skewed.
You have to break that train of thought and realize, that it is not a fair comparison to group 2 engine types by internal or external size, which everyone does by nature. The fact is you are comparing a diesel that weighs almost twice the weight of the gas engine, and costs 2-3 times the price.
Compare same priced gas engine to a same $$ diesel, and you will likelyvfind your longevity results will be very even. Because for the same $$ you can buy a much more powerful gas engine that could be run much less loaded.

I know what you're saying, just not sure I agree with it. I think you have to take the same size gas and Diesel engines, run them side by side for the same task and see the outcome. Lets just say for arguments sake that the diesel lasts exactly twice as long, but costs twice as much. Well then that would be a tie race, if you were comparing dollar value. Actually you would also need to factor in the cost of swapping out the second gas engine, to complete the task at hand.

It just seems that this would be the most fair comparison IF you are comparing dollar value of the two. But if I remember right, the title of this thread is "which engine lasts longer", not which is a better value. Either way I still say the diesel would win by a long shot.

 

[redcentinela]

Everything being equal what motor will last the longest, Diesel or gas???

Any engine with proper maintenance should last many hours. Diesel's tend to last longer because contruction is heavier than gas engine

 

[RobertN]

Gas can last a long time. My comparison would be the 1941 Farmall A, and Kubota B8200 I used to have. Both were in the 20hp range, and had similar torque curves.

The Farmall motor was about 2x the displacement of the Kubota diesel(113ci vs ~56.6ci from memory).
The Farmall motor red-lined at about 1600rpm(again, from fuzzy memory)
The Farmall motor used more gas per work unit.

After having that old tractor though, I bet that low rpm low compression motor would run forever, if maintained properly.

The biggest thing that stood out to me with that tractor was the 2x displacement vs the diesel.

 

[Carl Bert]

Gas can last a long time. My comparison would be the 1941 Farmall A, and Kubota B8200 I used to have. Both were in the 20hp range, and had similar torque curves.

The Farmall motor was about 2x the displacement of the Kubota diesel(113ci vs ~56.6ci from memory).
The Farmall motor red-lined at about 1600rpm(again, from fuzzy memory)
The Farmall motor used more gas per work unit.

After having that old tractor though, I bet that low rpm low compression motor would run forever, if maintained properly.

The biggest thing that stood out to me with that tractor was the 2x displacement vs the diesel.

<img src="http://www.tractorbynet.com/forums/attachment.php?attachmentid=291196"/><img src="http://www.tractorbynet.com/forums/attachment.php?attachmentid=291195"/>

I just love those old Farmall's.

 

[DarkBlack]

I know what you're saying, just not sure I agree with it. I think you have to take the same size gas and Diesel engines, run them side by side for the same task and see the outcome. Lets just say for arguments sake that the diesel lasts exactly twice as long, but costs twice as much. Well then that would be a tie race, if you were comparing dollar value. Actually you would also need to factor in the cost of swapping out the second gas engine, to complete the task at hand.

It just seems that this would be the most fair comparison IF you are comparing dollar value of the two. But if I remember right, the title of this thread is "which engine lasts longer", not which is a better value. Either way I still say the diesel would win by a long shot.

I see you have the normal "mindset" I was refering to Forget it's an engine comparison. Think as if you are comparing T.V.s.
You have for the comparison, let's say $800. You can get a real big plasma, and compare it to a much smaller LED.
So say you have $5k for the engine comparison. 5K buys you a nice big 400hp V8 gas engine. for $5,000 in diesel, you might get a 3 of 4 cylinder 40 HP engine. Now go put thos 2 engines in the same vehicles ( truck, tractor ). The big gas engine can be geared and run at a much lower relative load, and should last as long or longer. The same principal goes for weight.