1998 V70 awd fuel economy

I have a 98 V70 awd that someone did a T5 swap in so it?s basically an R without the interior and trim. The awd works and I overall really like the car. Only issue is the fuel economy. I?m getting anywhere between 15 and 17 mpg. I have a check engine for an evap leak but nothing else. I?ve done plugs, wires, and cap and replaced some vacuum lines. Still need to do the PCV on it. I don?t drive really hard. My 94 850 turbo wagon got 22 mpg all year long. Does the awd really cause that big of a drop in fuel economy? I don?t want to start throwing parts at it if it really can?t be increased. I only really use the car in the winter so I?ve been considering getting another 740 or 940 wagon instead for the winter months.

10% Ethanol-winter blend fuel can increase consumption 10-20%.
I would guess AWD increases consumption by a few mpgs too.

I'd say you could probably get a couple mpg more but awd probably takes a good bit of mpg away. Do the air filter, fuel filter while you are doing maintenance. Keep the tires pumped up to the firmer side of air pressure. A slow reacting 02 sensor might not throw a code but could affect mileage a bit. Even the pcv being done will help mileage as the engine won't be fighting internal pressure. Also use a good synthetic oil.

It looks like you are getting the kind of fuel mileage expected for that particular car.

https://www.fueleconomy.gov/feg/noframes/14453.shtml

EPA mileage for the 1998 V70 AWD is 16/23, so you're not that far off the mark. I drove a 1997 V70R for years, and it got about 25-26 mpg on the highway if I kept it under 80.... which was hard.

if you have just the stock T5 2.4L turbo, that's not the R version. The R was a 2.3L high-pressure turbo, with 3 programmed performance settings that could be toggled by the driver (E: economy, T: touring, and S: sport). That was before Volvo turned the R into an appearance package only.

How's it run? Zoom-zoom OK? If so, I think you're fine. Drive it a bit and see if it gets worse before worrying too much about it.

chronicrhythm said:

I have a 98 V70 awd that someone did a T5 swap in so it’s basically an R without the interior and trim. The awd works and I overall really like the car. Only issue is the fuel economy. I’m getting anywhere between 15 and 17 mpg. I have a check engine for an evap leak but nothing else. I’ve done plugs, wires, and cap and replaced some vacuum lines. Still need to do the PCV on it. I don’t drive really hard. My 94 850 turbo wagon got 22 mpg all year long. Does the awd really cause that big of a drop in fuel economy? I don’t want to start throwing parts at it if it really can’t be increased. I only really use the car in the winter so I’ve been considering getting another 740 or 940 wagon instead for the winter months.

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I recall a friend having an AWD volvo of that vintage and it was getting somewhere in the low twenties. 20-21 most of the time, a lot of highway driving. I'd say you are in the ballpark for winter conditions.

Did the person who swapped the car do anything to it at all outside of just bolting up the stock stuff? If it is an automatic does it have the right transmission computer (I don't recall if they are all that different or not). A swap automatically makes me think things may have been monkeyed with.

If they just used the T5 block, it's not an improvement per se, since you just dropped displacement. Even if they used the 15g (or 16T, depending on which T5) - unless they also swapped the ECU, you are likely to use more fuel (since it's AWD) than with the stock 2.4l LPT motor....

Anyway, the mileage still sounds on par. Should be better on long highway drives, but for local/town driving sounds pretty good. I still miss my 98 AWD

I'm not sure what MPG my '98 AWD gets. I'd guess 20-23 mpg off the top of my head. I replaced the 13C with a 16T and the car has a tune.

Sounds about right. Those things like to have little vac leaks in a few spots. They can all add up to a couple of MPG

dmg4 said:

EPA mileage for the 1998 V70 AWD is 16/23, so you're not that far off the mark. I drove a 1997 V70R for years, and it got about 25-26 mpg on the highway if I kept it under 80.... which was hard.

if you have just the stock T5 2.4L turbo, that's not the R version. The R was a 2.3L high-pressure turbo, with 3 programmed performance settings that could be toggled by the driver (E: economy, T: touring, and S: sport). That was before Volvo turned the R into an appearance package only.

How's it run? Zoom-zoom OK? If so, I think you're fine. Drive it a bit and see if it gets worse before worrying too much about it.

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Thanks for the response! It runs great and has good pickup. Although it?s slower by a bit than my 94 850 turbo wagon. Pretty positive it has the 2.3 with 16t according to the previous owner. I need to check the computers.

lookforjoe said:

If they just used the T5 block, it's not an improvement per se, since you just dropped displacement. Even if they used the 15g (or 16T, depending on which T5) - unless they also swapped the ECU, you are likely to use more fuel (since it's AWD) than with the stock 2.4l LPT motor....

Anyway, the mileage still sounds on par. Should be better on long highway drives, but for local/town driving sounds pretty good. I still miss my 98 AWD

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Pretty sure it got a 2.3 block with 16t turbo. I need to check the computers and see if they swapped that too. Highway gets a little better for sure. That car looks mean! Looks like some big turbo stuff going on.

spock345 said:

I recall a friend having an AWD volvo of that vintage and it was getting somewhere in the low twenties. 20-21 most of the time, a lot of highway driving. I'd say you are in the ballpark for winter conditions.

Did the person who swapped the car do anything to it at all outside of just bolting up the stock stuff? If it is an automatic does it have the right transmission computer (I don't recall if they are all that different or not). A swap automatically makes me think things may have been monkeyed with.

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I?m pretty sure they swapped the block and the 16t but I?m not sure about the computers. I?ll check the computers. It doesn?t like to keep the torque converter locked around 50mph but that could be the extra weight of the car. Sadly when I got the car the persons wife threw away all the paper work when she cleaned it. So I have no idea what maintenance has been done. I?ve done timing belt, vacuum hoses, high flow air filter (which probably doesn?t help fuel economy) and other routine maintenance. I?ll look into the computer numbers and see if anything is different from a 2.4 turbo transmission computer and the T5

chronicrhythm said:

Pretty sure it got a 2.3 block with 16t turbo. I need to check the computers and see if they swapped that too. Highway gets a little better for sure. That car looks mean! Looks like some big turbo stuff going on.

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Yeah, I had a Precision 6262bb turbo on it by that point. 500AWHP before I broke the piston lands.

Would think skinny pizza cutter standard P80 steelies on 195-65-15 (I think that's the stock P80 base model tire size???) & N/A or 2.4LPT might help one of those heavy 4-speed auto-tragic AWD porridge stirring turds out a bit?

16-17mpg the '98 V70Rs city/urban loop mixed routinely not even driving like a jerk or in the worst heavy traffic per se...just all that stuff/porridge to spin up, only 4 gears, low compression small displacement engine in a big heavy car & runs real rich in cold weather it seems too unless heated?

But on the stock 16" meteors pumped up it'd get 28-29 highway so I don't think there was anything *wrong* with it.
Not for lack of trying / tore my hair out going thru it & just gave up in exasperation & decided to drive a truck/SUV w/manually dis-engageable 4wd w/low range, no finnicky CV joints (against my religion) w/awd not made out of glass (is it just that they're neglected & people gun it out of a slick driveway & a corner abruptly hooks up/really catches & breaks things more than them being silly weak?), skid plate & radiator up nice & high outta harm's way (I didn't realize those were so exposed/vulnerable hanging way down & way forward in the nose in P80s unless you buy an all alum rad & decent skid plate for them?) & no T-belt to change that could tow or pull its own self around town w/some torque/no boost needed.

*want* to like P80s, really do & could do a lot worse? They're in the JYs still, decent length 8-year model run w/some parts interchange...

IDK what the ultimate practical P80 recombine is to really beat on one like I like to do anymore & not worry/think about it much.
Some kinda Swedish cop white '98 V70 no sunroof, no power seats, XC cladding/lift/bumpers & aftermaerket skids, C70 'Vert solid bushing x-member & brace, M66 & tall skinny pizza cutters on steelies crammed over the stock police 302mm brake setup / vented rear discs?
Some creative RV-tow style driveline decoupler, switch to power haldex off & unlock the rear hubs to save fuel & wear & tear?
Seems like it'd be labor intensive/hard to sell if you ever did decide to sell tho (hence mostly sticking w/super clean 5-speed P80s & V70Rs)

That said, unloaded, the N/A LH3.2 5-speed 49-state/CA NOX failing no-EGR or airpump 850 is the hipermiler of the stock P80s.
Unloaded, it can actually get 22-23 city & 32-33 highway.
They're maybe somewhat less aerodynamically 'noisy' than a 2/7/9 underneath w/suitcase mufflers/cat downpipe & the like, but they're still remarkably bad that way compared to even a classic SCAAB 900.

Kjets On a Plane said:

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That said, unloaded, the N/A LH3.2 5-speed 49-state/CA NOX failing no-EGR or airpump 850 is the hipermiler of the stock P80s.
Unloaded, it can actually get 22-23 city & 32-33 highway.
They're maybe somewhat less aerodynamically 'noisy' than a 2/7/9 underneath w/suitcase mufflers/cat downpipe & the like, but they're still remarkably bad that way compared to even a classic SCAAB 900.

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I know of a couple stick p80 wagons around but the people aren?t looking to sell. I?m considering going back to an 850 wagon. I have one that needs some work but would be the perfect winter beater. Thing is I love the v70 too. The nautic blue is really nice. Maybe I should just remove the driveshaft and call it good. I have 185/65/15 studded tires at the moment. Pretty skinny tires. Or I just sell it and get a 2/7/9 series wagon

Edit: Sorry, 205-55-16 stock V70R tires *shoulda disclosed that just to be fair.

V70 AWD base models IIRC have 15" pizza cutters, not big balloons to ruin economy to spin up or be a barn door in the wind like the XCs...

How are your driving conditions? Lots of snow and lowish temperatures? I have a B9 Audi A4 Allroad and it displays instantaneous, short term and long term fuel economy. Summertime on the highway I am running about 5.2 - 5.3 l/100km (44 mpg) as long as there is no head wind and I don't have the roof rack on. With a good tail wind I have hit 4.7 l / 100km. Winter with lots of fresh snow and cold temperatures (-20C), and Mich snow tires I can be running around 10 l /100 km (23 mpg). Ploughing through snow really increases the rolling resistance / drag on the car and in the case of the Audi the frequency of engagement of the mid clutch (or Volvo's viscous coupling). I have seen the instantaneous numbers hit 15-17l / 100 km when you hit a significant section of fresh snow. Mix that with cold weather and nasty fuel consumption is a reality.

If this is true

I only really use the car in the winter

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don't compare the fuel economy to the long term economy of a year around driver. The extra weight and the higher ride height will extract a fuel penalty that might be 2-3 mpg. Everything else is probably due to the driving conditions.

I was out this morning getting some stuff. By the time I was doing this it had warmed up all the way to -25C. Including about 90 seconds of warm up time, the trip fuel economy for running around came in at something a sniff better than 17l / 100 km. Cold weather, warm up time and crawling traffic because of ice fog at traffic lights = bad fuel economy.

Kjets On a Plane said:

Not for lack of trying / tore my hair out going thru it & just gave up in exasperation & decided to drive a truck/SUV w/manually dis-engageable 4wd w/low range, no finnicky CV joints (against my religion) w/awd not made out of glass (is it just that they're neglected & people gun it out of a slick driveway & a corner abruptly hooks up/really catches & breaks things more than them being silly weak?),

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See, this simply isn't (wasn't) true - and is a common myth spread around the interwebs . One of the main reasons I built my wagon back then. The VC coupler locks solid (50/50) torque split once you reach around 300AWHP (so not on any stock turbo).



The AG & rear diff (with 700 series posi) hold up OK if serviced. The spline coupler between diff & AG. was the weak point, same as most versions used by Volvo on later AWD 5pots. I converted mine to M66 - I would never have tried that with the autotragic, besides my intense dislike of automatics as a rule.


The front CV fails dues to cat proximity & then strains the AG pinion bearing & seal. Servicing the CV's in a timely manner kept the AG intact.

Haldex versions cannot be tweaked to the same extent - unless you have external control of the module to alter torque split, it will stay with factory 70/30 no matter what on all the P1 P2 variants.

This does happen if you hard launch the P80 with too much torque available (drag strip runs). Rolling starts are pretty much a must

I had to replace the driveshaft and cross member support last year due to rust. The pillow bearing had broken free of the support from the rust. The driveshaft would flop around under certain circumstances.

No other issues though.