New Member Introduction
 

Hi everyone, I'm Steve, I live in suburban Kansas City, MO, and I'm glad to be here. While I'm new to the forum, I'm not really new to hypermiling. For the last five-plus years, I drove a 2005 Scion xB MT, and there was a small group of people on the ClubxB forums who worked to maximize fuel economy. I didn't keep meticulous records, but based on my Ultragauge long-term readouts (reset annually the last three years), I got between 37 and 38 over the time I owned the car. The updated EPA combined rating is 28.

With the Scion totaled by an inattentive driver a couple of weeks ago, I just bought a 2013 Buick LaCrosse eAssist. Since people on the Buick forums aren't really talking about maximizing fuel economy, I figured I'd come to the source. Looking forward to figuring out how to get greater than the EPA combined 29 in that boat, and to contribute what I do know.

Thanks!

Funky vehicle. Welcome! That eAssist is the system with the extra-powerful alternator that helps on acceleration, isn't it?

http://static.usnews.rankingsandrevi...e_sideview.jpg

http://www.buick.com/content/dam/Bui...870x329-16.jpg

This site says the Cd is 0.30 - 0.33 ... I guess it depends on aero packages. Do you know which you have?

Yup, the eAssist uses an electric motor in place of the alternator, with batteries that take up about 2 cubic feet of trunk space. It provides an additional 15 hp and 79 ft-lb under acceleration. It also uses auto-stop when you'd otherwise be idling without the AC going, and has a more aggressive DFCO.

The .33 drag coefficient is for the V6 models. The 4-cylinder with eAssist got some aero tweaks, like a different underbody tray, a lip on the trunk lid, and active flaps behind the front fascia to force more air around the car, rather than through the engine compartment. The cooling system has 2.6 quarts more capacity to make up for that.

This is the first automatic transmission I've had as a daily driver in 11 years, and I have no idea how to boost fuel economy numbers like I did with the manuals. At roughly 130 miles into my first tank (15.8 gallons), I'm still just above the 3/4 mark on the fuel gauge, and the onboard FE readout puts me at 29.2. Not bad, but plenty of room for improvement.

Thanks for the welcome!

Welcome to EM Steve. It'll be interesting to see what you can do with the Buick!

Are you looking to modify it in any way?

It seems to me that the eAssist operating paradigm is similar to that in my Honda Civic Hybrid. The only difference is that you have an auto where mine is a manual.

Without looking closely at the specifications on your auto, I couldn't recommend EOC. Too often that'll just lunch your tranny.

What's your commute like? Mostly city, mostly highway, mix?

Thanks for the welcome! First, I'm going to see how well-calibrated the odometer and onboard FE gauges are. If necessary, I'll use the Ultragauge I had in my old xB for better data. Second is probably tires with a taller sidewall. The stock tires are 235/50 on 17" wheels, and I'm thinking a 55 or 60 series will help. I went with taller tires on the '05 xB I had before the Buick, and it made a difference.

Beyond that, I'll have to see what suits it best. Since it's a newer car, my wife isn't too hip to the idea of mods beyond installing factory options it didn't come with. But we'll see.

I'm not sure how similar the system is to the Honda - I'm just digging into some of the details of the GM system, and I'm not too familiar with Honda's.

I won't do EOC with this car - I didn't do it much with my MT xB, either. Regen braking seems to activate when coasting in gear with the engine on, so I'll have to see what happens in neutral. One drawback of the onboard FE gauge is that its readout maxes out at 99 mpg (and often). In the xB, I saw 400+ on the UG many times.

My current job isn't FE friendly, but it could be worse. I drive nearly 30 miles from one suburb to another, but I'm going in the same general direction as a lot of commuters who live in MO and work in KS. My boss lets me work 7-4, which helps, particularly in the morning. I can take many different routes both ways, from 90% highway to 100% city traffic and suburban boulevards.

I think the main thing with a car this size is to pick a route that allows me to maintain momentum as much as possible. The car, a full tank of gas, and my bloated backside put total weight over 4100 lbs, while my old xB came in under 2800 with me and a full tank. I'll have to do some testing of different routes to find the right balance of time and economy.

After today's commute, the onboard FE gauge shows 30 mpg even, so I'm doing something right.

Is the 99 mpg reading indicating DFCO? My 2005 Camry does DFCO even while coasting in neutral.

I think it is. I noticed your post earlier today, and checked it out this afternoon. Even at low speed, coasting in gear puts the instant FE at 99 mpg. Shifting to neutral causes it to drop. Shifting back into Drive puts it back at 99.

If it does deceleration fuel cutoff in neutral the engine will stall. The only thing that prevents the stall in gear is the momentum of the vehicle.