250k on engine, 40mpg in winter reasonable?

[Jesse]

I was just wondering what anyones thoughts on this would be. On non ecomodding websites I have been laughed at, as if my 91 civic si's fuel economy isn't anything to be proud of. Before I did ecomodding I would get 29-31mpg in the winter(with no engine warm up) and 32-34 in the summer, heavy hwy miles.

Last week here in MN we had mostly single digit temps while I was driving, one night of 51 miles it was below zero. That was my last tank and I achieved 42.93mpg. I usually see 38-40 now, but I decided to shift under 2k rpm, and stay below 65mph(about 3k rpm), seemed to pay off.

What do you think would be a realistic number for summer temperatures? Take into account that over 70 degrees I will roll one or more windows down since I have a 51 mile commute to work. So then I expect the numbers to plummet. But then again I will more than likely ride my motorcycle if it's not raining.

I am hoping to see 45-48mpg combined in 60 degree temperatures. Thanks!

mods:
front air dam w 60% grill block, rear wheel skirts, roof extension, partial undertray, tires at 44psi, deleted pass side mirror, mudflaps, moonroof deflector.

[Frank Lee]

Don't read too much into one tank's results but yeah summer fe will be better.

[SentraSE-R]

About 140% of '08 EPA if it's an automatic, or 170% of EPA if it's a manual, and you're willing to work for it.

[bestclimb]

The 1.5 in my 95 is pretty similar to the 1.5 in your 91, I have better FE gearing I think. This winter I have been getting tanks in the 45mpg range. Depends on how bad you want it. I could do better but I like having a heater that is putting out hot air so I forgo a bunch of opportunities to shut the engine down. Summer I get mid 50s. I don't have much in the way of aeromods just driving slow, using the engine only when I need it and not touching the brakes except for the last 25mph of deceleration.

[BrianAbington]

as long as the compression in your engine is good and your fuel system is clean and works properly there is no reason your car shouldn't put up huge numbers.

[bluejoey]

Originally Posted by bestclimb

The 1.5 in my 95 is pretty similar to the 1.5 in your 91, I have better FE gearing I think. This winter I have been getting tanks in the 45mpg range. Depends on how bad you want it. I could do better but I like having a heater that is putting out hot air so I forgo a bunch of opportunities to shut the engine down. Summer I get mid 50s. I don't have much in the way of aeromods just driving slow, using the engine only when I need it and not touching the brakes except for the last 25mph of deceleration.

Nice! I also have a 1.5 in a 95, but an auto instead of a manual. My last tank was a 38 from a mixture of city and highway, which is 131% of my combined EPA of 29. I got an Ultragauge and am probably around 32 on my current tank , which is all city, and is therefore 123% of my city EPA of 26. 40 from a 1.5 engine in winter is definitely possible; the single greatest mod you can make is in driving technique. I want to see if I can crack 140% of my city EPA before winter is done. That would be a mileage of 36.4.

To the OP, it is important to note that it's more useful to compare your mileage to your EPA estimates than to an arbitrary number like 40. For example, it's more impressive to hit 30 in a car with a 20 estimate than it is to hit 40 in a car with a 30 estimate. The former is a 150% of EPA score, but the latter is a 133%. Both are impressive, but you're saving more fuel (and using more skill) to beat your EPA by 50% in the first case than by 33% in the second, even though the 40 initially seems more impressive.

[Jesse]

Originally Posted by Frank Lee

Don't read too much into one tank's results but yeah summer fe will be better.

I understand that.

Originally Posted by bestclimb

The 1.5 in my 95 is pretty similar to the 1.5 in your 91, I have better FE gearing I think. This winter I have been getting tanks in the 45mpg range. Depends on how bad you want it. I could do better but I like having a heater that is putting out hot air so I forgo a bunch of opportunities to shut the engine down. Summer I get mid 50s. I don't have much in the way of aeromods just driving slow, using the engine only when I need it and not touching the brakes except for the last 25mph of deceleration.

I don't shut the engine off, but I do coast to most stops.

Actually I have the 1.6l D16a6. I know the gearing in your vehicle is more FE friendly than in my civic si, I used to own a 1995 civic dx coupe when I was a teen.

88-91 Si D16A6
1st 3.250
2nd 1.894
3rd 1.259
4th 0.937
5th 0.771
R 3.153
FD 4.25

92-95 Civic DX/LX D15B7
1st 3.250
2nd 1.762
3rd 1.172
4th 0.909
5th 0.702
R 3.153
FD 4.058 coupe/sedan 3.888 hatchback

2008 EPA for my vehicle 24/29

http://www.fueleconomy.gov/feg/calcu...lumn=1&id=7621

Originally Posted by BrianAbington

as long as the compression in your engine is good and your fuel system is clean and works properly there is no reason your car shouldn't put up huge numbers.

Well the injectors have 250k miles on them. Last winter I had to replace the o rings, they had all crumbled... but at the time I didn't care about fuel economy so much. I have thought about replacing the injectors.

Thanks for the replies guys.

[bestclimb]

I forgot to mention I have well in excess of 250,000 miles. The odometer when I replaced the cluster read about 250,000 but it had been misbehaving for years (dropping to zero for extended periods of time). I have no idea how many miles it went like that prior to me buying it and replacing the cluster over a year later.

With the gearing of your car pulse and glide could work out well for you if you want to bother with that technique.

If you care to set up a kill switch for EOC I have a how too up for 4th gen civics but I suspect that earlier generations would be compatible.

When I eoc and pulse and glide I get over 50mpg in the city, while only getting 40s on the highway drive in.

I had a 91 crx si years ago, before I thought about driving economically I usto get 30mpg driving it like I stole it. It had 350,000 miles on it and it was going strong when I sold it.

[eagletalon]

To me your 40mpg is incredible considering the miles and year of your car and add the winter into the mix that is pretty awesome milage if you ask me.