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Volvo V70 MPG-Real World Numbers

40 messages,  Last post on Jun 25, 2009 at 2:17 PM

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What is this discussion about? Volvo V70, Fuel Efficiency (MPG), Wagon

Messages Page 3 of 4

#20 of 40 2004 168 hp NA V70 5A tranny by jim314

May 22, 2007 (4:37 pm)

Roundtrip Dallas to New Orleans May 18-21, 2007: Over 4 days I drove 1220 miles in my 2004 Volvo V70 2.4L normally aspirated 168 hp 5-cyl 5A trans, consuming 36.5 galUS of gasoline, for an average of 33.4 mpgUS (7.03L/100km and 40.1 mpgUK). The US EPA mpg estimates on the 2004 168 hp NA V70 are 22/30 mpgUS city/hwy (10.7/7.83 L/100km, 26.4/36.0 mpgUK). The tires are the base 195/65-15 Michelins (max infl press 51 psi) inflated to 37 psi. Load driver only and light cargo load.
 
Right now when I fuel up I am mixing approx equal parts of 93 octane and 89 octane (or I use approx 2 plus 1 of 93 and 87) to get 91 octane. The manual says that 87 octane is the minumum which the engine can use, but 91 or greater is recommended for optimum operation. I want to get the absolute best mpg and don't want to hole a piston if the knock sensor would fail. The Volvo normally aspirated 2.4L 5-cyl has a compression ratio of 10.3:1.
 
Here's how the legs worked out:
 
Dallas to Ville Platte LA, nearly all IH20 and IH49 with speed control set at 67 mph: 366.5 mi/10.644gal => 34.4 mpgUS => 6.82 L/100km, 41.3 mpgUK. Camped at State Park and slept in the V70.
 
Ville Platte to New Orleans and back to New Iberia via US90, nearly all regular hwy and significant local in New Orleans and in New Iberia: 399.9 mi/12.929 gal = 30.9 mpgUS => 7.60 L/100km, 37.1 mpgUK.
 
New Iberia to Dallas, virtually all IH with speed control set at 68 to 70 mph: 453.4 mi/12.937 galUS = 35.0 mpgUS => 6.71 L/100km , 42.0 mpgUK.

#21 of 40 Passing technique by jim314

May 25, 2007 (6:27 am)

Replying to: jim314 (May 22, 2007 4:37 pm)
On my recent trip to New Orleans I decided to set the speed control to about 68 mph and try to stay in the right lane. I was trying to get the highest mpg I possibly could. I did pass some cars that were going slower, but my idea was to just keep a constant speed and not have to summon the concentration required for passing. Most of the cars that passed me were going significantly faster than 70 mph and staying mostly in the left lane or making frequent lane changes so, in my opinion, my going slightly under the speed limit presented no additional obstruction to them.
 
What I did find was that large trucks would come up behind me and then change to the left lane and pass with clearly increased speed and fuel use. I cannot stand to have an 18-wheeler right on my tail and I don't want to obstruct them. It occurred to me to change to the left lane as the trucks approached and let the trucks pass in the right lane. The truck drivers seemed happy to do this. This is how the lead is changed in a bicycle pace-line.
 
I would change to the left lane and coast down using the negative button on the cruise control to minimize the time I was beside the truck and then shift back to the right lane and speed up to 68 mph after the truck had opened a gap. I suppose the truck drivers have trained some car drivers to do this and that must be the reason they come up close behind before changing to the left lane to pass. I figure this really saves fuel--a negligible amount in my car but a lot in the truck. I was not in a hurry on this trip.
 
As the truck would approach from the rear in my lane I would first signal a lane change, check that no vehicle was overtaking in the left lane (which wasn't a problem because the traffic on IH49 was light and not heavy on IH20), then change lanes. In the left lane I would slow down with the -button on the speed control so as to minimize the time I was alongside the truck, then signal and change back to the right lane after the truck passed. Then I would accel back to cruising speed with the + button on the speed control.
 
Another way I handled the speed control was to change to the left lane then disengage the cruise control so as to slow down quickly. As soon as the truck came alongside on my right I would signal a change back to the right lane, and after the truck passed, change lanes, then accelerate back to near 68 mph with slight enough pressure on the accelerator pedal that the 5A transmission wouldn't downshift, then re-engage the speed control.
 
I found on this car that if I used the + button on the speed control or I re-engaged the speed control when the speed was significantly below the set point, then the speed control would cause a downshift, which I figured would use more fuel and cause more wear on the engine and transmission.
 
On a freeway in New Orleans I needed to pass quickly to get around a vehicle to get to an exit and gave full throttle at about 50 mph. The tach went up to well over 5000 rpm (redline is 6000). I don't like to do that very often.

#22 of 40 '06 V70 2.5T by ronsteve

May 28, 2007 (9:03 pm)

What jim314 describes is not passing technique, but hyper-miling. I think he might even be hyper-miling for other drivers, or at least the trucks for whom he moves left to allow them to pass.
 
My 2006 2.5T is over 11,000 miles (just bought it as a former dealer demo)...
  
first fill-up, all around-town commuting... 21.4 mpg (computer said 21.8, but no telling how much of what happened before I reset the meter on delivery.
  
Since then, the computer was showing 22.3mpg driving around town, then I reset before a highway trip from Wilmington(NC) to Raleigh. Just got home and it shows 28.5mpg (showed 29.3 when I got up there Sunday, but I did a little driving around Raleigh).

#23 of 40 Re: '06 V70 2.5T [ronsteve] by jim314

May 29, 2007 (6:51 am)

Replying to: ronsteve (May 28, 2007 9:03 pm)
Right now my in-town use of this 2004 base V70 2.4L non-turbo 5A is pretty short trips, and some local towing of a light trailer (~700 lb GW). The fillup just before this trip was 19.1 mpg. The usual range in-town is 19 to 23 depending on the predominant type of trips.
 
This base model doesn't have a trip computer and all my reported values are from trip odometer and gas station pump values.
 
Going from 20 mpg (0.050 gpm) to 35 mpg (0.0286 gpm) is a 43 % decrease in fuel use per unit distance travelled.
 
(Going from 20 to 35 mpg is a 75 % increase in distance travelled per unit of fuel consumed, but this is not the percent change that is relevant to how most people use their vehicles. What most people do is drive the distance they want/"need" to and pay what it costs. Most people do not buy a given amount of fuel in a given time period and drive until the fuel is exhausted.)

#24 of 40 '06 V70 2.5T revisited by ronsteve

May 31, 2007 (8:28 am)

I'm not sure what jim314's point is in the last post, but, ummm...ok.
 
Currently 2 tanks into my experience with a year-old V70. The pump-truth is this:
 
1st tank (all city-ish driving): 318.8 miles on 14.866 gallons for 21.4 mpg
 
2nd tank (70% highway at cruise speeds just either side of 75mph): 411.6 miles on 15.331 gallons for 26.8 mpg
 
I mentioned what the trip computer said just for the purposes of comparing its readout to real-world. The first tank made me think it was a bit optimistic, and the second, just the opposite.
 
At the start of my road-trip Sunday I reset the meter, with 58 miles on this tank and showing 22.3 mpg average. (theoretically 2.6 gallons consumed)
 
At the end of my 142-mile outbound highway trip, it showed an average 29.3mpg. However, I didn't reset anything then, or until I filled up. When I refueled yesterday, it read 27.2 mpg average over 353.6 miles since the earlier reset (theoretically 13.0 gallons consumed)
 
SO... this time around the computer might have been a little pessimistic, but not too too far out of line (the computer stats suggest it would have wanted 15.6 vs. the 15.3 it took). And so far, chalk up another car that has me close to the EPA estimates (21/29 on this one).

#25 of 40 Re: '06 V70 2.5T revisited [ronsteve] by jim314

Jun 08, 2007 (8:01 am)

Replying to: ronsteve (May 31, 2007 8:28 am)
Sometimes my posts have more than one point, and sometimes the point is obscure, if there is one. It's the way my undisciplined mind works.
 
But one point was that the US practice of using mpg values instead of gpm (i.e. gal of fuel consumed per mile travelled) is a barrier to doing proper fuel use comparisons. You really need to use the fuel/distance value like the Europeans do. They express fuel use as liters consumed per 100 km travelled (L/100km).
 
For example if vehicle B has a gpm value (or L/100km value) that is 20% less than vehicle A, then B will use 20% less volume of fuel to go any given distance. This is usually what people want to know.
 
But if vehicle D has an mpg which is 20% higher than vehicle C, then it does not mean that D will use 20% less fuel to go a given distance. It means that D will go 20% farther with any given volume of fuel. But this latter is not usually what people want to know.
 
In three tanks of mostly city driving we have gotten 17 mpg twice and 13 mpg once with this 3.2L 2WD XC-90.

#26 of 40 fuel/distance vs, distance/fuel by jim314

Jun 08, 2007 (9:41 pm)

Replying to: jim314 (Jun 08, 2007 8:01 am)
Suppose veh D gets 40 mpg and veh C gets 20 mpg. Vehicle D has a 100% higher mpg value than C, but for a given distance travelled veh D uses 50% less fuel than veh C.

#27 of 40 Re: fuel/distance vs, distance/fuel [jim314] by ronsteve

Jun 09, 2007 (5:38 pm)

Replying to: jim314 (Jun 08, 2007 9:41 pm)
We are firmly off topic here, but it is a US/European thing. Watch some car racing... in the States the media talk about how fast the lap was in MPH. With European racing (and the actual racers in US forms like NASCAR) the discussion centers on lap time, as that is how they know how far ahead (or behind) they are, and at what rate the gap is changing. And you're right... it makes more sense! When I'm running, I look at my pace (minutes per mile) and not mph... tho I do switch back to MPH on bike rides that tend to cover more open and indefinite courses!
 
OK, so that keyed a lot more on MPH than MPG... but it shows the US/Euro divide, be it speed vs. lap time, or MPG vs. actual consumption.
 
Back on topic, more pseudo-city driving in my '06 2.5T... a lot of 45 mph speed limits, but enough lights and stop-and-go that my trip computer shows average speeds around 26 mph...
359.9 miles on 15.729 gal for 22.9 mpg (or 4.37 gal/100mi)
  
The computer was claiming just 21.8 mpg, but this may have been more of a "short fill" than the last one. It's easy to squeeze a LOT of fuel into this tank after the auto-shutoff, and last time I put close to 3/4 of a gallon in after it kicked off.
 
Even if this fill was a half-gallon shorter than the last, my actual mpg would have been 22.2. Starting to think (now that I know how it's being filled up, etc.) that the computer is a little pessimistic.
 
And maybe I'll stop topping off now, tho that will make fuel mileage calculations less of a "controlled" situation.

#28 of 40 Re: fuel/distance vs, distance/fuel [jim314] by blckislandguy

Jun 20, 2007 (6:35 pm)

Replying to: jim314 (Jun 08, 2007 9:41 pm)
Guys, at 9:30 PM at night it hurts my head to read this stuff.
 
My experience in our 2001 XC70 during recent summer driving:
 
1) on highway MPG at 70-75 MPH is 24.5 MPG
 
2) around town MPG is 18.5 MPG or less depending on nature of trip.
 
Keep in mind that Volvo's burn premium. While 24.5 MPG on an interstate at 75MPG sounds great, the car is consuming $3.29 per gal self service premium. I'd rather have lower MPG with burning a non-premium grade.

#29 of 40 Re: fuel/distance vs, distance/fuel [blckislandguy] by jim314

Jun 20, 2007 (10:35 pm)

Replying to: blckislandguy (Jun 20, 2007 6:35 pm)
Volvo gets a good combination of performance and fuel economy from their engines by setting up the engine to work best on 91 octane or above. But if you read the owner's manual it states that the Volvo engines can run on 87 octane AKI, which is what it shown on the pumps in the US.
 
If the cost of the fuel is a problem for you and if you are not driving agressively or towing a trailer, then maybe you would want to use 87 octane. To me the extra cost of premium is negligible, and even though I drive with a light foot, I don't want to depend on a knock sensor to save my engine from damage.
 
"In many parts of Europe, 95 RON (90-91 AKI) is the minimum available and the standard, with 97/98 being premium or "super". In other countries "regular" unleaded gasoline, when still available, is sometimes as low as 85 RON (still with the more regular fuel - 95 - and premium around 98 available.)" http://en.wikipedia.org/wiki/Octane_rating

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