Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

Please follow the links below to help get you started!

Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 3 Series & 4 Series > E90/E91/E92/E93 (2006 - 2013)

E90/E91/E92/E93 (2006 - 2013)
The E9X is the 4th evolution of the BMW 3 series including a highly tuned twin turbo 335i variant pushing out 300hp and 300 ft. lbs. of torque. BMW continues to show that it sets the bar for true driving performance! -- View the E9X Wiki

Thread Tools Display Modes
Old 03-14-2014, 12:57 PM
loubob loubob is offline
Registered User
Location: Denver, Colorado
Join Date: May 2010
Posts: 26
Mein Auto: 135i Conv. & X5 35d
328i xDrive SULEV

I feel kinda dumb. I've been a BMW owner since 1995 and have owned quit a few of them. My latest purchase is a CPO'd 2011 328i xdrive SULEV. I only now found out that the car is "rated", if thats the correct term, a SULEV, or super ultra low emmisions

I started investigating what a SULEV was and could not find a satisfactory answer. It was somewhat confusing regarding N51 vs. N52, loss of power, more expensive to maintain, etc. Can someone set the record straight for me?

Reply With Quote
Old 03-14-2014, 01:54 PM
fdriller9 fdriller9 is offline
Officially Welcomed to the 'Fest
Location: NJ/Philly
Join Date: Oct 2006
Posts: 7,890
Mein Auto: '06 AW 330xi
It's a low emissions vehicle for the California market. Maybe some others.

I know one thing is that if the coolant temp sensor goes bad in the radiator, you have to replace the entire radiator. It's welded in.

Power might be slightly less due to more restrictive emissions standards but it will be minimal.

| LCI Msport Conversion | Exotic Tuning Front Lip | H&R Coilovers | M3 Subframe Bushings | Custom Polyurethane Shore A90 Tension Strut Bushings | E93 M3 23.6mm Rear Sway Bar | UUC Front Sway Bar | Custom Heim Joint Rear Control Arms | Apex ARC-8 | Dunlop Direzza ZII Star Spec | Modified Dinan Cold Air Intake | aFe Oiled Drop-in Filter | Custom Hand-Made LED Angel Eyes | Alpine MRP-M500 | Custom LED Reverse Lights | OEM Blacklines | BMW Performance Trunk Spoiler |
Reply With Quote
Old 03-14-2014, 02:15 PM
loubob loubob is offline
Registered User
Location: Denver, Colorado
Join Date: May 2010
Posts: 26
Mein Auto: 135i Conv. & X5 35d
fdriller, the radiator issue was one of those mentioned. Other issues were the PVC being an integral piece of the valve cover so if something went wrong with the PVC you have to replace everything. Another issue was the fuel pump being integral with the fuel tank. Again, fuel pump craps out and you have to replace the tank too. According to the dealers records the car was leased here in Colorado has lived its entire life here. Gez, who can you trust if you can't trust your BMW SA?

Thanks for the response.
Reply With Quote
Old 03-14-2014, 02:38 PM
mr_bean mr_bean is offline
Officially Welcomed to the 'Fest
Location: NJ
Join Date: Mar 2009
Posts: 723
Mein Auto: 2000 328i
The raditor temp sensor is very reliable. Failure is rare.
PVC system is the same as the non SULEV IIRC.
Integral fuel pump was only on older SULEV engines. The N51 has a replaceable pump.
Power and torque figures are the same.
Only real differences are lower compression, addition of VANOS and SAI in the N51. I think the cats are different too. There's a few other minor differences that can be found if you Google hard enough.

Sent from BimmerApp mobile app
Reply With Quote
Old 03-14-2014, 03:35 PM
alpinweiss alpinweiss is offline
Officially Welcomed to the 'Fest
Location: Nuevo México
Join Date: Sep 2009
Posts: 2,183
Mein Auto: E46, E83, E90 (all MT)
The sealed fuel system (integral fuel pump, fuel filter, sending unit, etc.) was on E46 models with the M56 engine. It is crazy expensive, if you ever have to pay to have it replaced. But the warranty is very long on it.

The N51 engine (SULEV) has some good features and some bad features. Some of the emissions-related components are more expensive than the N52 parts. But, most emissions components on the SULEV models are warranted for 12 years/120,000 miles, or for 15 years/150,000 miles. Fuel system components are replaceable individually. They are expensive, but not insane. Power and driveability are about the same for the N51 and N52 engines.

E46, E83, E90 (all with three pedals)
F25 (missing third pedal)
BMW CCA member
Reply With Quote
Old 03-14-2014, 03:39 PM
wilt wilt is offline
Officially Welcomed to the 'Fest
Location: SF Bay area
Join Date: Jan 2014
Posts: 2,759
Mein Auto: 2011 328i
"Super ultra-low emission vehicle (SULEV) is a U.S. classification for passenger vehicle emissions. The classification is based on producing 90% less emissions than an equivalent gasoline-powered vehicle. SULEV is a stricter standard than LEV (Low Emission Vehicle) and ULEV (Ultra-Low Emission Vehicle), however not as strict as PZEV (Partial Zero Emission Vehicle)."

"In California, manufacturers of SULEVs can be given a partial credit for producing a Zero Emission Vehicle (ZEV) and so a vehicle of this type can be administratively designated as a Partial Zero-Emission Vehicle (PZEV). In order to qualify as a PZEV, a vehicle must meet the SULEV standard and, in addition, have zero evaporative emissions from its fuel system plus a 15-year/150,000 mi (241,402 km) warranty on its emission-control components.

"In the case of hybrid vehicles this warranty is extended to the electric propulsion components (electric motor/generator/starter, battery, inverter, controls) and their mechanical interface to the driveline - potentially a distinct advantage to the owner of such vehicle."
SULEVs emit substantially lower levels of hydrocarbons, carbon monoxide, nitrous oxides and particulate matter than conventional vehicles. The SULEV standard steps up the ULEV, Ultra Low Emission Vehicle standard.

BMW N51 Overview
In order to comply with SULEV requirements, the N51 is another variant of the N52
engine. There are various measures to meet the EPA/CARB standards, some of which
are familiar from the previous SULEV (M56) engine.
Some of the SULEV measures for the N51 include:
• Near engine catalyst with additional underbody catalyst
• Secondary air system
• Optimized combustion chamber geometry in cylinder head
• Modified piston crown for lower compression
• Plastic valve cover with integrated crankcase vent valve and separator (from N52KP)
• Stainless steel fuel lines with threaded connections
• Radiator with "Prem-air" coating
• Throttle system - EGAS08 carried over from N52KP
• Airbox with Activated carbon filter for EVAP control
• Purge system pipes are made from "optimized" plastic
Someone on another forum noticed, with 2011 e92 SULEV, manual transmission, RWD, " In all gears but 3rd, when you let off the gas pedal, the throttle closes (completely) and reopens at about 1000 rpm (just in time for idle). In 3rd gear the throttle opens for idle at 2600 rpm. This causes a noticeable instantaneous decrease in deceleration and continued decreased deceleration thereafter). All this can be verified beyond a doubt by watching the instantaneous gas mileage display. When engine braking in any gear but 3rd, the indicator is at 99 mpg (max) right down to 1000 rpm. In 3rd
gear it drops from the 99 mpg reading at 2600 rpm." This behavior was not only in his car, but also in two other manual tranny 2011 SULEV at the dealer.

Someone else added, "Another difference is that if the N51 is coupled with an automatic transmission, the transmission has a N51-specific mode of operation. That is, during the engine warm-up phase, the transmission will automaticlly shift to neutral when the vehicle comes to a stop. When you release the brake pedal, the transmission shifts back into gear. This behavior reduces load on the engine when it's cold, further reducing emissions. Once the engine has sufficiently warmed up, the transmission behaves like any other automatic typically does," and then added, " there was a N51 dyno posted on this site (or maybe it was E90post) recently and it showed that peak horsepower and torque numbers are the same, though the N51 has slightly more area under the curve in the low- to mid-range. This is undoubtedly due to the DISA 3-stage intake manifold that the N52 lacks. The trade-off is that you can feel the changeover points for the intake manifold on the N51 (though they are slight) as engine speed climbs, whereas the N52 is very linear from idle to redline."

Last edited by wilt; 03-14-2014 at 03:50 PM.
Reply With Quote
Old 03-15-2014, 04:53 AM
f30jojo f30jojo is offline
Officially Welcomed to the 'Fest
Location: North Carolina
Join Date: Jun 2013
Posts: 1,604
Mein Auto: 2012 X5 35d
Im pretty sure the n52 has a 3stage intake (330i 530i x3 3.0si z4 3.0si) the 325-525 ect have single stage. Theres different tech updayes for the n52. Ranging from 212hp to 255hp with the n53 (euro only) at 275hp.

Sent from BimmerApp mobile app
Reply With Quote

See More Related BMW Stories

Forum Navigation
Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 3 Series & 4 Series > E90/E91/E92/E93 (2006 - 2013)
Today's Posts Search
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump

All times are GMT -7. The time now is 02:53 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
© 2001-2015 performanceIX, Inc. All Rights Reserved .: guidelines .:. privacy .:. terms