Smart Car of America Forum banner

1 - 20 of 32 Posts

·
Registered
Joined
·
1,606 Posts
Yep, those are the firgures in the other mpg post. I don't have a problem using higher octane since our tank is only 8.5 gallnos and I will be adding bold-ons to boost the mileage. I STILL WANT MY SMART! :)
 

·
Smart A**
Joined
·
1,141 Posts
Compression Ratio

Has anyone seen the specs on compression ratio? I suspect it's high to get the 71hp/1000cc, and hence the need for higher octane.
 

·
Senior Smartie
Joined
·
1,263 Posts
I seem to recall Fish having gotten them somewhere

Has anyone seen the specs on compression ratio? I suspect it's high to get the 71hp/1000cc, and hence the need for higher octane.
Because I recently posted a response to it. I think it was with regard to the Brabus and the turbo it has making 86hp and the normally aspirated 71 hp engine having a higher compression ration due to it not having the added power created by turbo. I think the Brabus with 86 hp has 10:1 compression and the US model has 11.4:1. You would think that would be the other way around but as my memory can recall, the use of a turbo at the higher compression ratio of 11.4 may compromise the integrity of the engines lower end perhaps so they lowered that to be able to gain the benefits of the turbo. Not sure about this but it makes sense to me with my knowledge of engine design/building.
Fish will know for sure as he wrote the original post that I responded to.
 

·
Banned
Joined
·
3,834 Posts
Rog..O. 11.4:1 for the 61PS and 71PS normally-aspirated gassers, and 10:1 for the 84PS and 98PS (Brabus) turbos.

BTW, the Brabus turbo is recommended to use 98 RON gas (about 94 PON here). Does Sunoco still sell 94 street gas?
 

·
Banned
Joined
·
3,834 Posts
Wikipedia/Regular Unleaded

(Then I find:

http://en.wikipedia.org/wiki/Mitsubishi_3B2_engine

3B2-
Engine type Three cylinder, DOHC
Displacement 999 cc
Bore x stroke 72.0 x 81.8 mm
Fuel type Regular unleaded gasoline
Peak power 50 kW (68 PS) at 6000 rpm
Peak torque 92 N·m (68 ft·lbf) at 3000 rpm


I'm so confused over the octane rating.

Aaron Lephart)

The Wikipedia entry is probably correct, but the engine noted is the 3B20 which has only 8.8:1 CR, thus allowing the regular unleaded. Our engine is derived from the 3B2 family and is a bit different. I don't know what its current designation is, 3B21 maybe. Maybe just call it a 3B2x for now.
 

·
Registered
Joined
·
86 Posts
I'm interested in the statement of mods to increase the gas mileage on the US car??

How about a new thread on mods that will increase the gas mileage, if we know them yet??
 

·
Smartmadness.com
Joined
·
1,216 Posts
I'm interested in the statement of mods to increase the gas mileage on the US car??

How about a new thread on mods that will increase the gas mileage, if we know them yet??
Excellent I idea...I would like to know more about this aswell. Like could a Turbo, Brabus Exhaust, or air intake give better gas mileage and increase horse power . PLEASE PLEASE LET ME KNOW
 

·
Banned
Joined
·
3,834 Posts
Brabus-izing

Doesn’t look like “Brabus-izing” is the key to better fuel mileage: the ’07 smart coupés Euro combined fuel mileages are 61PS – 60.1; 71PS – 60.1; 84PS turbo – 57.6; and 98PS turbo Brabus – 54.3 (all in Imperial gallons).

With fuel mileage such a deal in the U.S., you can bet that the smart designers have done everything practical to get the numbers up.
 

·
Smart A**
Joined
·
1,141 Posts
I think the Brabus with 86 hp has 10:1 compression and the US model has 11.4:1. You would think that would be the other way around .
Not really. Most turbo cars have a lower compression ratio than their normally-aspirated counter-parts. With the heat build-up from the turbo, you have to worry about detonation.
 

·
smart happens here!
Joined
·
1,830 Posts
Doesn’t look like “Brabus-izing” is the key to better fuel mileage: the ’07 smart coupés Euro combined fuel mileages are 61PS – 60.1; 71PS – 60.1; 84PS turbo – 57.6; and 98PS turbo Brabus – 54.3 (all in Imperial gallons).

With fuel mileage such a deal in the U.S., you can bet that the smart designers have done everything practical to get the numbers up.
I agree, I've never come across a performance mod that increases fuel mileage - most are out for more horsepower, which usually doesn't translate to more mpg's.

Nothing will beat proper tire inflation and not having a heavy foot! ;)
 

·
Smart A**
Joined
·
1,141 Posts
Rog..O. 11.4:1 for the 61PS and 71PS normally-aspirated gassers, and 10:1 for the 84PS and 98PS (Brabus) turbos.

BTW, the Brabus turbo is recommended to use 98 RON gas (about 94 PON here). Does Sunoco still sell 94 street gas?
On the east coast, they lowered their top grade to 93 R+M/2 (PON).
Their 4 grades now are regular 87, Plus 89, premium 91 and Ultra 93.
 

·
Registered
Joined
·
834 Posts
FWIW

My current sedan has an old EPA rating of 18 26 with 21 average

New EPA rating of 16 21 with 19 average

The manufacturer recommends high test or 91 octane


I use 87 octane gas

Actual mileage 20.4 28 average about 23

So, unless the HP to weight ratio, effect is much larger than on my car, I do not foresee a great loss of economy with regular (87 octane) fuel.

Also FWIW when the need arises I do not hesitate to put my foot down and I usually drove "with" traffic on the highway.

I am not sure I see a real problem
 

·
Smart A**
Joined
·
1,141 Posts
I agree, I've never come across a performance mod that increases fuel mileage - most are out for more horsepower, which usually doesn't translate to more mpg's.

Nothing will beat proper tire inflation and not having a heavy foot! ;)
On the MINI, some performance mods can lead to enhanced fuel economy as long as you can avoid the temptation of utilizing the additional performance. What's the likelihood of that?:D
 

·
Registered
Joined
·
1,606 Posts
Mind you be sure of the quality and only tried and true add ons.

Cold air intake/ K & N for example
Larger bore throttle body
Hotter plugs and wires
Tuned Exhaust header
Hi Flow Catalytic converter
Tuned exhaust

This is general info. Once the car is out, aftermarket dealers will have more specific data on Quality products, how to....do's and don'ts. Let the hardcore boys test first. When the enthusiasts test it out we'll know what's good and what's bad. :) Also, remember your foot on the gas has a lot to do with it! LOL
 

·
smart happens here!
Joined
·
1,830 Posts
to my experience, most performance mods as those listed above lead to more horsepower and better "breathing", which usually equates to sucking in more gas too! my JCW mcs gets 3 - 5 mpg less for all its 30 or so extra horsepower.
 

·
Registered
Joined
·
1,606 Posts
It's all about how much you change and how you drive. My mileage improved and I added about 25-30 horsepower. I added all those things plus a lighter underdrive pulley. I still use 89 octane and get 30-32 mpg and on a long haul I got mid 40 mpg. No BS. If I chipped and went for a 60mm throttle body and straight back headers and one of those tin can mufflers, I'd get more hp but definitely lose mpg. I'd need hi octane. Also, as I said, if you have a lead foot you won't get good mileage anyway.
 

·
Smart A**
Joined
·
1,141 Posts
to my experience, most performance mods as those listed above lead to more horsepower and better "breathing", which usually equates to sucking in more gas too! my JCW mcs gets 3 - 5 mpg less for all its 30 or so extra horsepower.

Once I got the 15% reduction pulley and the LDG tune on my JCW (23 add'l whp), steady speed highway mileage went up a couple of points. In town mileage dropped, but that's because I can't keep my foot out of the pedal.:D
 

·
Registered
Joined
·
211 Posts
16
SmartBob
Pure Excitement




Join Date: Sep 2007
Location: S. Jersey Res# 1321
Vehicle: '98 Dodge Neon R/T
My SCOA Gallery Mind you be sure of the quality and only tried and true add ons.

Cold air intake/ K & N for example
Larger bore throttle body
Hotter plugs and wires
Tuned Exhaust header
Hi Flow Catalytic converter
Tuned exhaust

This is general info. Once the car is out, aftermarket dealers will have more specific data on Quality products, how to....do's and don'ts. Let the hardcore boys test first. When the enthusiasts test it out we'll know what's good and what's bad. Also, remember your foot on the gas has a lot to do with it! LOL
NOW THATS SMART!!!!!!!!!!!!!!!!!!!!!!!
 
1 - 20 of 32 Posts
Top