by Patrick Rall
Fiat has become one of the most fuel efficient automakers in the European market, and a big part of that is due to their MultiAir technology. According to the folks at Motor Trend, Chrysler is currently working with this technology on the existing 2.0 and 2.4 liter 4-cylinder engines, the 3.6L Pentastar and an upcoming version of the Pentastar V6 measuring 3.2 liters. When combined with the strides made by Chrysler to improve the fuel economy of these engines through additions of items like the new ZF-designed 8-speed automatic transmission, the MultiAir technology could help make future Chrysler models among the most powerful and fuel efficient models available in the US market.
The MultiAir system uses a computer-controlled electrohydraulic inlet valve lift
and duration control system to meter the amounts of air to enter the
individual cylinders. This essentially works to add the perfect amounts of
air into the combustion chamber, allowing the engine to run more
efficiently compared to similarly sized engines, even while the MultiAir
engines offer more power. Fiat has found that their MultiAir technology improves horsepower output
by 10% and torque output by 15%, while also improving fuel economy
measures by 10% compared to similar engines devoid of the
The only downside to this technology thus
far is that its effectiveness fades as the engine roars past 7,000 rpm –
which is why Fiat has only used the design on their smaller, lower
performance engines, as opposed to the high performance engines offered
by Fiat’s Ferrari brand. However, the engines designed by Chrysler for
the American market rarely reach those kinds of RPM ranges, so applying
this technology to Chrysler’s 4- and 6-cylidner engines should go a long
way in allowing the company to increase power relative to the
competition while also improving fuel economy ratings…but what about the
Chrysler has done a great job of designing the modern Hemi engine lineup
to offer great power while also achieving impressive fuel economy
numbers. At first, only the “standard” 5.7L Hemi V8 received the
addition of features like Chrysler’s Multiple Displacement System, which
effectively shuts down 4 of the 8 cylinders when full power isn’t needed. But as that technology has advanced, even the mighty 392 cubic inch
Hemi V8 in the SRT lineup features Chrysler’s “fuel saver” technology.
Imagine Fiat’s MultiAir technology applied to that 392 Hemi. Adding 10%
more horsepower and 15% torque would amount to a total output of 517
horsepower and 541lb-ft of torque while also upping the fuel economy
ratings to the range of 15.4mpg around town and 25.3mpg on the highway.
Adding 10% more horsepower, 15% more torque and 10% better fuel economy
to the modern Hemi lineup would benefit Chrysler’s performance cars and
their popular Ram pickups. And based on news from Motor Trend – we could
soon see a MultiAir-assist Hemi V8 that serves as one of the most
powerful and efficient engines available in the American market.
Will MultiAir make it’s way into the mighty Hemi? Sound off in the Forums!