Modern Vespa

I've read a bit about engines improving over time.

Curious as to whether people have felt this with Vespas?

And at what mileage did it seem to improve?

Engines can improve as they wear in. This was especially true back when cylinders were great slugs made of iron and needed to be properly broken in when new. My Royal Enfield improved markedly over the first 10,000 km, I found myself regularly adjusting the carb to slow the idle down as the engine was loosening off. Transmission shifting will also improve as the shifting mechanism loosens off due to initial wear.

I don't believe modern engines change nearly so much as they bed in as modern construction techniques such as plated aluminium cylinders and far tighter manufacturing tolerances allow engines to work far better and require less break in time right out of the box.

My GTS, a good example of a modern ride, now has 40,000 km on it and really hasn't changed notably since it was new.

So yes, engines can improve or change as they age, but I would say the higher the quality of the engine, the less that change will be. Some cheap turd of an engine however will improve quite a bit as it breaks in and then begin that slide towards needing its first rebuild, the cheaper the engine, the faster the slide.

What I experience in most of the cars I had is that fuel consumption shows a slightly decreasing trend when mileage is increasing. Not dramatic, maybe 0.2 - 0.3 l/100km over a 100.000km.
As an example the yearly average fuel consumption graph of my 2006 Renault Grand Scenic 1.5dci. I had it for almost 6 years and did 160.000km with it.[/img]

It depends on the engine type I suppose. Vespa? Maybe not so much but I imagine you can certainly screw one up if you rode it like you stole it from there get-go as certain components I imagine still need to settle in. Now my Ural? Yeah well it's a Ural and a not-so-very-modern boxer engine and I can absolutely feel a performance boost now that the engine has settled in. Mind you no matter how well broken in it is it's not like I'll ever be running with the devil on it. Modern BMWs I've owned I honestly really can't tell the difference but then again I keep swapping them out. Talk to me in a few years as I plan to hold on to the GSA.

I feel my 07 GTS 250 started to improve as it approached 20k. It was a pleasant surprise. The water cooled engines of today are mfg' ed with much closer tolerances that the air cooled ones of days gone past. Now with 30k trouble free miles (smiles).
Good News: It will be warm enough to ride on Thursday and Friday!!!
Tony in Tn.

Here's the km/l of my primavera from 2000 to 11000 km. Steady drop.

If I see that trend I would be a little worried and ask myself the question: why is fuel consumption going up.

This is how my fuel consumption looks like on the BV 300.
Starts at 9000km and goes to 26000.

It is in l/100km. Opposite to your km/l. So lower is better.
Typically fuel consumption is lower in summer than in winter. Below the black average line is summer and above is winter.
But on average there is a slight, although not significant, general trend towards better fuel efficiency. And I think that is what you should expect.

On the whole, I'd say mine is improving with age.

My 2 cents…Engines are definitely improving. Better casting techniques. Stronger metal alloys Better machining, gaskets, better fit at the mating surfaces. AND don't forget better lubricants.

I had a small but noticeable improvement in both top end and mpg after about 2,000 miles on my 18 GTS. Nothing earth haltering maybe 2-4% on mpg and 3 mph on the top end. First noticed riding with my husband who had a 19 GTS that had less than 1,000 miles on it. Once his reached 2,500 the difference was more down to riding style as we switched scoots a couple times to see if it was the rider to the scooter.