turbo for better mpg

[Piwoslaw]

+1

If you had to replace the engine, then you could go with a smaller one and turbo it, but just slapping a turbo on won't help fuel economy much, if at all.

Originally Posted by cRiPpLe_rOoStEr

I'd rather get an intercooler.

An intercooler helps only on turbodiesels. On normal diesels it doesn't do anything (other than restrict the intake), nor on gassers as in this case.

jm283611, swap the tranny and replace your tires with slightly taller ones when the time comes, this will reduce rpms at highway speeds. Also, add a warm air intake, ie so your engine is getting intake air from the warm engine bay, not the cooler outside. Warm air is less dense than cold, so less air gets into the cylinder, and with it less fuel.

Since you mostly do highway driving, then you would greatly benefit from aeromods - smooth wheel covers, partial grille block, smooth bellypan, rear wheel skirts. A Kammback or even boattail would do wonders to you FE

[ksa8907]

Turbochargers do increase efficiency, but only at less than 2 lbs boost. More than that and the ecu crams more fuel in

Think pumping loses

[pete c]

Turbos help diesels get better mileage. They can increase efficiency of a gasser, but, that means they will make more power at wide open throttle. This doesn't help you any at improving mileage at 60 mph. It all keeps coming back to that PITA throttle (which a diesel doesn't have). What good is it to boost the I/P pressure if the throttle will just close a bit? It's the same thing for CAI.

[RobertISaar]

Originally Posted by Frank Lee

The reason "they" say turbos can increase fuel economy is for those situations when a much smaller displacement turbocharged engine is fitted instead of a bigger naturally aspirated lump. Sticking a turbo onto whatever is already in there will not result in fuel savings.

and here is the problem with this whole idea....

the turbine housing is actually a significant restriction in the exhaust and causes a considerable jump in backpressure. now you have to overcome that resistance as well, and resistance is about the last thing you want when looking for efficiency increases.

if you're going to gain fuel economy(with a gas engine) with a turbocharger, it's not going to happen compared to an otherwise identical engine without the hairdryer. a lower displacement or otherwise significantly better thermal efficiency is required to see a boost in MPG.

[arcosine]

I'd doubt you would be running boost on the highway, And I doubt you would see any mph gain. Try a hot air intake first.

[Jakins]

ok, so i had a turbo on my civic back when i though racing hondas was cool. before that i got around 40 mpg, with the turbo im not totally sure what it was, but it was like 32-35? MAYBE i cant remember, bottom line is, it was less. and this was set up as good as it could get for mpg (cuz im cheep) at first i had bigger 310 injectors and the entire time i was not running a secondary o2 sensor, as well as im pretty sure the boost blew my pcv valve out and i had no idea about it and i had onle a 4 inch down pipe and no exhaust. but then i put some stock integra injectors in. it was better. i had no tune and a small intercooler. about 5-7 psi of boost. MAYBE if you ran super tiny boost and got a real nice tune you could see an increase. but running stock injectors with boost is what killed my old engine. the only thing that is for sure about turbos is it will make your car faster. i was able to beat v8 mustangs lol. you might be able to get the same MPG as before but it will take tuning. its a very expensive way to get a gain in mpg though. dont take my word for it though, im not exactly the smartest person in the world. i just have a tiny bit of experience in that field.

[oil pan 4]

Originally Posted by Frank Lee

The reason "they" say turbos can increase fuel economy is for those situations when a much smaller displacement turbocharged engine is fitted instead of a bigger naturally aspirated lump. Sticking a turbo onto whatever is already in there will not result in fuel savings.

Or "they" are talking about diesel engines.

[cRiPpLe_rOoStEr]

Originally Posted by Piwoslaw

An intercooler helps only on turbodiesels. On normal diesels it doesn't do anything (other than restrict the intake), nor on gassers as in this case.

When I said I'd rather get an intercooler, I should've said I wouldn't get rid of it, alongside the turbo. Since it would lead to a colder intake temperature, would reduce the risk of pistons overheat while running leaner

[Frank Lee]

Originally Posted by oil pan 4

Or "they" are talking about diesel engines.

Could be any ICE I suppose, but see "Ford Ecoboost" and the like.

[cRiPpLe_rOoStEr]

Remember, it's not just 'bout consumption, a turbo can also help to get less emissions. In some Brazilian cities there are already environmental inspections, and often turbocharged engines have better results than its naturally-aspirated counterparts since the combustion process is more complete, leading to lesser HC and carbon monoxide emissions.